IAER 


IOLOGY    AND 


rxC\ 


NEWYORK=CINCiNNAT!^CHICAGO 
AMERICAN  BOOK  COMPANY 


!      ! 


LIBRARY 

OK   THK 

UNIVERSITY  OF  CALIFORNIA, 

OR 


Received 


Accession  No.  /^/.  332   •    Class  No. 

B4OI  OGY  f      ' 


Physiology  Primer 


PRIMER 


PHYSIOLOGY 


AND 


HYGIENE 


A  TEXT-BOOK  FOR  PRIMARY  CLASSES.  WITH  SPECIAL 
ERENCE   TO   THE   EFFECTS   OF  STIMULANTS  AND 
NARCOTICS  ON  THE  HUMAN  SYSTEM 

BY 

WILLIAM    THAYER    SMITH,    M.D, 

PROFESSOR  OF   PHYSIOLOGY   IN   DARTMOUTH   MEDICAL  COLLEGE. 


NEW   YORK    •  :  •    CINCINNATI    -  :  •    CHICAGO 

AMERICAN    BOOK    COMPANY 


FROM  THE  PRESS  OF 
IVISON,  BLAKEMAN  &  COMPANY. 


BIOLOGY 


Copyright,  1885,  by 

IVISON,  BLAKEMAN,  TAYLOR  &  Co. 
7       3  3  Z. 


PREFACE. 


IN  studying  the  body,  it  is  very  desirable  that 
the  scholar  should,  as  far  as  possible,  see  and  han- 
dle the  parts  described.  Children  especially  can 
learn  much  more  readily  in  this  way  than  from 
any  description.  A  dissection  of  a  cat  or  dog  or 
rabbit,  illustrating  the  lessons,  will  make  the  text 
clear,  and  fix  the  essential  facts  in  the  mind. 

Or,  if  this  can  not  be  done,  pieces  of  muscle  and 
of  cartilage,  joints  and  bones,  a  heart,  the  lungs, 
a  liver,  an  eye,  and  other  organs,  can  be  obtained 
from  the  butcher,  to  serve  the  same  purpose. 

The  apparatus  mentioned  in  illustration  of  the 
action  of  organs  —  the  bellows,  the  syringe,  and 
others  that  may  occur  to  the  teacher  —  should  be 
shown. 

Models  and  plates  are  also  valuable.  A  few 
clear  ideas  of  the  structure  and  functions  of  the 


PREFACE. 


body  will  be  worth  much  more  to  the  children 
than  many  details  imperfectly  understood. 

On  the  subject  of  stimulants  and  narcotics,  I 
have  endeavored  to  make  no  statements  which  are 
Hot  susceptible  of  positive  proof,  and  to  present 
only  facts  which  children  are  capable  of  appreciat- 
ing. Much  more  might  be  said  which  does  not 
come  within  the  province  of  such  a  work  as  this. 

WILLIAM   THAYEE,   SMITH. 
HJLKOYEB,  N.H.,  May  1, 1885. 


CONTENTS, 


CHAPTER    I. 

PAGE 

INTRODUCTION  .»,.».« , 9 

Anatomy,  Physiology,  Hygiene. 

CHAPTER    II. 
THE  BODY „....„,...,      11 

Sect.  I.  Divisions  of  the  Body.  —  Sect.  II.  The  Skin,  Perspi- 
ration. The  Hair.  Sebaceous  Glands.  The  Nails.  Care  of 
the  Skin.  Bathing.  Things  to  be  avoided.  Effects  of  Alcohol 
and  Narcotics. 

CHAPTER    III. 
THE  MUSCLES  ......    .    .    .    .    .,.,,....      24 

Sect  L  What  Muscle  is.  What  Muscle  does.  Walking.  Ten- 
dons. How  Muscle  contracts.  —  Sect.  II.  Exercise.  Expres- 
sion of  the  Face.  Things  to  be  avoided,  —  Sect.  III.  Effects 
of  Alcohol  and  Tobacco. 

CHAPTER    IV. 

THE  HEART  AND  BLOOD-VESSELS ,    ,    ,      35 

Sect.  L  What  the  Blood-vessels  are.  Arteries.  Capillaries. 
Veins.  The  Heart.  A  Journey  through  the  Heart  and 
Blood-vessels.  Action  of  the  Heart.  Effects  of  Alcohol  and 
Tobacco. 

CHAPTER    V. 

THE  BLOOD. —WEAR  AND  REPAIR. — THE  LYMPHATICS  ...      50 
Sect.  L  Amount  of  Blood.   Corpuscles.    Contents  of  the  Blood. 
How  Waste  Matter  goes  out.    Lymphatics.    Fainting.   Purity 
of  the  Bloodo    Effects  of  Alcohol  and  Tobacco. 


6  CONTENTS. 


CHAPTER    VI. 

PAGE 

FOOD  AND  WATEB.  —  STIMULANTS  AND  NARCOTICS 60 

Sect.  I.  Nourishment.  Animal  and  Vegetable  Food.  Cooking. 
Water.  Eating  and  Drinking  Habits.  —  Sect.  II.  What  a 
Stimulant  is.  Tea  and  Coffee.  Opium.  Tobacco.  Alcoholic 
Drinks. 

CHAPTER    VII. 

DIGESTION. — ABSORPTION 76 

Sect.  I.  The  Inside  of  the  Body.  What  Digestion  is.  The 
Teeth.  Mastication.  The  Stomach.  The  Bowels.  The  Liver. 
The  Pancreas.  —  Sect.  II.  What  Absorption  is.  Dyspepsia. 
—  Sect.  III.  Care  of  the  Stomach.  —  Sect.  IV.  Effects  of 
Alcohol  and  Tobacco. 

CHAPTER    VIII. 

RESPIRATION. — THE  VOICE 95 

Sect.  I.  Air.  The  Lungs.  The  Trachea.  The  Nose.  The 
Larynx.  The  Vocal  Cords.  The  Bronchial  Tubes.  Breath- 
ing. Color  of  the  Blood.  —  Sect.  II.  Effects  of  Alcohol  and 
Tobacco. 

CHAPTER    IX. 

THE  NERVOUS  SYSTEM.  —  THE  EYE.  —  THE  EAR 108 

Sect.  L  The  Brain.  The  Spinal  Cord.  Action  of  the  Nervous 
System.  Paralysis.  —  Sect.  II.  The  Eye.  Description  of  its 
Parts.  Action  of  the  Eye.  Care  of  the  Eyes.  —  Sect.  III. 
Description  of  the  Ear.  — -  Sect.  IV.  Effects  of  Alcohol  and 
Tobacco. 

CHAPTER    X. 
T:rjE  FRAMEWORK 130 

Sect.  L  The  Vertebrates.   Description  of  the  Bones.  —  Sect.  II. 

Joints.    Different  Kinds  of  Joints.     Parts  of  a  Joint.  —  Sect. 

III.   Structure  of  Bone.  —  Sect.  IV.  Care  of  the  Frame.  — 

Sect.  V.  Effects  of  Alcohol  and  Tobacco. 

GLOSSARY 141 

INDEX  .  143 


(UNIVERSITY 


LIST  OF  ILLUSTRATIONS. 


FIG.  PASE 

1.  SKIN  OF  THE  PALM  (MAGNIFIED),  SHOWING  RIDGES  AND  PORES     .  14 

2.  SWEAT-GLAND,  WITH  SMALL  BLOOD-VESSELS  SURROUNDING  IT    .    .  15 

3.  VERTICAL  SECTION  OF  THE  SKIN,  SHOWING  ROOTS  OF  HAIRS    .    .  16 

4.  MUSCLES  OF  THE  BACK 25 

5.  BICEPS  MUSCLE 26 

6.  MUSCLES  AND  TENDONS 28 

7.  THE  ARTERIAL  SYSTEM  (COLORED) 33 

8.  CAPILLARY  PLEXUS  (MAGNIFIED) 36 

9.  DIAGRAM  OF  A  SECTION  OF  THE  HEART,  WITH  BLOOD-VESSELS  .    .  37 

10.  REPRESENTATION  OF  THE  CIRCULATION  OF  THE  BLOOD 39 

11.  SEMILUNAR  VALVES  PARTLY  CLOSED 41 

12.  RED  CORPUSCLES  OF  HUMAN  BLOOD  (400  DIAMETERS) 52 

13.  SUPERFICIAL  LYMPHATICS  OF  THE  ARM 55 

14.  THE  INTERNAL  ORGANS 78 

15.  THE  LOWER  JAW  AND  TEETH 79 

16.  BACK  TOOTH  SAWED  IN  TWO 80 

17.  A  PORTION  OF  THE  PAROTID  GLAND  (MAGNIFIED)       82 

18.  SECTION  OF  THE  STOMACH 84 

19.  THE  LIVER  AND  OTHER  ORGANS  OF  DIGESTION 86 

20.  THE  GILLS  OF  AN  EEL 95 

21.  THE  HEART  AND  LUNGS 97 

22.  THE  LARYNX 99 

23.  SECTION  OF  THE  LUNGS 101 

24.  BRONCHIAL  TUBES  AND  AIR-CELLS  (MAGNIFIED) 101 

25.  THE  CHEST 103 

26.  GENERAL  REPRESENTATION  OF  THE  NERVOUS  SYSTEM     ....  109 

27.  HALF  OF  THE  BRAIN,  AND  UPPER  END  OF  THE  SPINAL  CORD  .    .  Ill 

28.  NERVES  OF  THE  FORE-ARM  AND  HAND 113 

29.  LACHRYMAL  APPARATUS 119 

30.  THE  EYE 120 

31.  THE  EYEBALL  AND  OPTIC  NERVE. 121 


8  LIST   OF   ILLUSTRATIONS. 

FIG.  PAQK 

32.  THE  EAR 123 

33.  THE  SKELETON 128 

34.  THE  BACKBONE,  SAWED  IN  TWO,  LENGTHWISE 129 

35.  A  VERTEBRA 130 

36.  THE  SKULL 131 

37.  THE  UPPER  LIMB 132 

38.  THE  LOWER  LIMB 133 

39.  JOINTS  OF  THE  SKULL 134 

40.  THE  HIP-JOINT 135 

41.  THE  SHOULDER-JOINT 136 

42.  SKCTION  OF  THE  THIGH-BONE    .                                                       .  137 


PHYSIOLOGY  PRIMER 


CHAPTER  I. 


INTRODUCTION. 

SECT.  I. — 1.  When  we  were  very  young  chil- 
dren, we  did  not  need  to  know  much  about  our 
bodies.  Our  parents  took  care  of  them.  They 
managed  our  eating  and  drinking  and  sleeping. 
They  clothed  us,  and  tried  to  keep  us  in  good 
health. 

As  we  grow  older,  we  can  take  more  care  of 
ourselves.  But  we  can  not  take  care  of  our  bodies 
properly  unless  we  know  something  about  them. 

We  need  to  know  what  they  are  made  of;  what 
becomes  of  the  food  we  eat ;  what  things  are  good 
to  eat  and  drink,  and  what  are  bad ;  why  we 
breathe;  what  the  heart  beats  for. 

All  this  knowledge  is  called  Anatomy  and 
Physiology. 


10  PHYSIOLOGY   PEIMEE. 

2.  The  body  is  like  a  clock,  with  its  wheels,  and 
its  spring,  and  its  hands,  and  its  ticking.     If  we 
take  the  clock  to  pieces,  to  see  what  it  is  made  of, 
that  is   like  the  study  of  Anatomy.     Just  so  the 
bodies  of  animals  and  men  have  been  examined, 
to  see  what  they  are  made  of.     If  we  set  the  clock 
a-going,  and  watch   it  to   see   how  it   ticks   and 
strikes,  and  turns  its  hands,  that  is  like  the  study 
of  Physiology.     Just  so  learned  men  spend  a  great 
deal  of  time  in  watching  animals  and  men,  to  see 
how  they  move  and  eat  and  breathe  and  feel. 

When  we  have  learned  these  things  about  our 
bodies,  we  shall  know  how  they  should  be  taken 
care  of  in  order  to  keep  them  in  health.  This 
knowledge  is  called  Hygiene. 

3.  Many  grown    people   are   very  ignorant   of 
these  things.     They  abuse  their  bodies,  and  wear 
them  out  in  various  ways.     Drinking  intoxicating 
liquors,    and    smoking    or  chewing    tobacco,  are 
among  the  most  common  ways. 


QUESTIONS. 

SECT.  I.  —  1.  What  is  Anatomy  ?    Physiology  ? 

2.  What  may  the  body  be  compared  with  ?    What  is  Hygiene  ? 

3.  Are  we  all  acquainted  with  our  own  bodies  ?    Mention  a  com- 
mon way  of  abusing  the  body. 


TIIE    BODY.  —  TIIE    SKIN.  11 


CHAPTER  II. 


THE    BODY. 

SECT.  I. — 1.  When  we  look  at  the  body  of  a 
man,  we  notice  these  things  :  — 

(1.)  It  is  made  of  several  parts;  namely,  the 
head  and  neck,  the  trunk,  the  upper  limbs,  the 
lower  limbs. 

The  upper  limbs  are  divided  into  the  arm  (from 
shoulder  to  elbow),  the  fore-arm  (from  elbow  to 
wrist),  and  the  hand. 

The  lower  limbs  are  divided  into  the  thigh  (from 
hip  to  knee),  the  leg  (from  knee  to  ankle),  and 
the  foot. 

(2.)  If  we  draw  a  line  from  the  top  of  the  head 
down  on  the  backbone,  we  shall  divide  the  body 
into  halves,  which  are  just  alike.  Each  half  has 
an  eye  and  an  ear,  and  an  arm  and  a  leg.  True, 
we  have  but  one  nose  and  one  mouth;  but  nose 
and  mouth  have  two  sides,  which  are  alike. 

(5.)  The  whole  body  is  covered  by  the  skin. 

THE    SKIN. 

SECT.  II.  —  1.  The  skin  is  soft  and  smooth  and 
elastic.  It  fits  perfectly,  and  yet  is  never  tight,  as 


12  PHYSIOLOGY   PRIMER. 

new  clothes  sometimes  are.  It  is  about  one-tenth 
of  an  inch  thick,  and  it  has  two  layers.  When 
we  raise  a  blister,  the  top  layer,  called  the  cuticle, 
is  lifted  up  by  the  water  which  gathers  under  it. 
When  we  fall,  and  scrape  the  skin  off,  it  is  gener- 
ally only  this  same  top  layer  that  we  have  scraped 
off.  The  red,  sore  surface  which  is  left,  is  the  deep 
layer,  or  cutis.  If  we  really  scrape  away  the  whole 
thickness  of  the  skin,  it  is  a  serious  injury.  After 
a  blister,  the  skin  will  heal,  and  look  just  as  it  did 
before.  But,  if  both  layers  of  the  skin  are  torn  or 
cut  out,  a  scar  will  remain. 

2.  A  scar  is  a  piece  which  nature  puts  in  to 
patch  a  torn   skin.     Like   the  patch  on  a  boy's 
trousers,  it  never  looks  exactly  like  the  rest  of  the 
skin.     That  is  because  it  is  not  exactly  like  it.     It 
is  not  real  skin.     One  peculiarity  of  a  scar  is,  that 
it  keeps  shrinking  for  a  long  time.     If  a  child  gets 
a  deep  burn  on  his  neck,  the  scar  will  often  shrink 
so  much  that  it  will  draw  his  head  to  one  side,  and 
give  him  a  wry  neck.     If  the  burn  is  under  his 
arm,  the  scar  may  draw  his  arm  down  so  that  he 
can  not  raise  it  far  from  his  side.     On  his  hand,  it 
may  prevent  him  from  straightening  his  fingers. 

3.  It  is  very  important  when  a  deep  burn,  or 
any  other  injury  that  takes  out  a  part  of  the  skin, 
is  healing,  to  have  it  properly  attended  to.     By 


PEESPIRATION.  13 


care,   the   scar  may  be   kept  from   drawing   too 
much. 

4.  Dandruff  is  from  the  outer  layer  of  the  skin 
on  the  head.     When  the  scalp  is  dry,  these  little 
scales   come   off   in   great    numbers.      Just    such 
scales,  only  smaller,  are  coming  off  all  the  time 
from  every  part  of  the  skin.     They  are  rubbed  off 
with  each  movement  that  we  make.     But  they  are 
so  fine  that  we  do  not  see  them.     In  this  way  the 
skin  is  continually  wearing  off;  and,  if  it  did  not 
grow,  it  would  soon  be  all  worn  away.      But  it 
grows  down  in  the  deep  layer  as  fast  as  it  wears 
off  on  the  surface. 

PERSPIRATION. 

5.  If  you  touch  the  face  of  a  person  sick  with 
a  fever,  you  will  find  that  it  is  hot  and  dry.     The 
skin  of  a  well  person  has  a  different  feeling.     It 
is  moist     When  the  air  is  very  hot,  or  you  have 
been  playing  hard,  you  can  see  the  moisture  stand- 
ing in  drops,  or  running  down  in  streams. 

We   call   this   perspiration,  or  sweat.      Where 
does  it  come  from? 

6.  On  the  ends  of  your  fingers,  you  can  see  that 
the  surface  of  the  skin  is  all  in  ridges,  with  furrows 
between.     With  a  strong   magnifying-glass,  these 
ridges  would  look  as  they  do  in  the  figure  (Fig.  1). 


14 


PHYSIOLOGY    PRIMER. 


You  would  see  on  the  ridges  little  holes,  which  are 
represented  by  the  black  dots  in  the  figure.     Just 

such  little  holes  are  in  the 
skin  all  over  the  body.  We 
call  them  pores.  There  are 
as  many  as  2,500,000  of  them 

7.  The     pores    are    the 
mouths  of  little  pits,  or  wells, 
which  are  called  the  sweat- 
glands, 

These  wells  are  tubes  about 
one-fourth  of  an  inch  long, 
which  run  down  nearly  to 
the  under-surface  of  the  skin, 
and  there  eid  in  a  coil. 

8.  The  sweat  is  constantly 
rising  in  these  tubes,  and  flowing  over  on  the  sur- 
face.    Ordinarily  it  dries  off  immediately,  and  we 
can  not  see  it.     When  we  are  very  warm,  it  comes 
faster  than  it  can  dry  ;  and  we  feel  and  see  it. 

9.  But  where  do  these  tubes  get  the  sweat  ?  By 
examining  with  the  microscope,  it  has  been  found 
that  the  coils  at  the  bottom  of  the  tubes  are  all 
covered  with  a  network  of  very  small  blood- 
vessels. The  blood  is  partly  water;  and,  as  it  flows 
through  these  little  vessels,  some  of  the  water 
soaks  through  their  walls,  and  through  the  walls 


Fige  lm 

nidges  in  the  skin  of  the 

The  Black  Spots  are  the  Pores. 


THE    HAIE.  15 


of  the  sweat-gland;  and  so  these  glands  are  con- 
tinually  filling,    and    flowing 
over. 

The  sweat-gland  is  like  a 
spring  in  which  water  is  al- 
ways bubbling  up  from  streams 
down  under-ground. 

1C.  Since  each  one  of  the 
tubes  is  about  one-fourth  of  an 
inch  long,  and  there  are  about 
2,500,000  of  them,  you  can 
easily  estimate  the  length  of 
the  tube  that  would  be  made  if  Sweat.GlaJ'^'smanbiood. 
they  were  all  joined  in  one.  vessels  surrounding  it 

More  than  a  pint  of  water  passes  off  through  the 
pores,  from  the  body  of  a  man,  in  a  day. 

THE    HAIR. 

11.  A  dog  or  a  horse  has  hair  all  over  his  skin. 
So  has  a  man ;  but,  on  the  most  of  his  body,  it  is 
so  short  and  thin  that  you  can  scarcely  see  it. 
The  reason  for  this  is  plain,  when  we  remember 
that  man  has  skill  and  hands  to  clothe  himself, 
and  the  dog  and  the  horse  have  not.  Therefore, 
Mother  Nature,  who  takes  good  care  of  even  her 
dumb  children,  makes  the  hair  grow  thick  to  keep 
them  warm.  She  did  not  intend  that  men  should 


16 


PHYSIOLOGY    PRIMER. 


cover  their  heads  as  they  do  their  bodies,  for  eyes 
and  ears  and  nose  and  mouth  must  be  kept  open. 
So  she  gave  us  long  hair  on  our  heads  to  protect 
them  in  part. 

Hair  is  beautiful  as  well  as  useful.  Each  hair 
has  its  root  at  the  bottom  of  a  tube,  which  rung 
down  from  the  surface  to  the  under  side  of  the 
skin. 

SEBACEOUS    GLANDS. 

±2.  Besides  the  sweat-glands,  there  are  other 
glands  in  the  skin,  called  sebaceous  glands. 

They  are  little  sacs, 
with  a  tube  leading 
from  them.  They 
give  out  an  oily  fluid. 
On  the  face,  they  are 
rather  large.  Some- 
times they  get  full  of 
Fig.  s.  the  fluid,  which  be- 

SECTION  OF  THE  SKIN,  SHOWING  ROOTS      pnrnpq   fVnVlr     qnrl    tVlPTl 
OF  HAIRS. -1.  Muscles   attached  to  the      '  CK>  anQ 

hair-sac.    2.  Sebaceous  glands.  tUmS      black.  When 

these  black  spots  are  squeezed,  their  contents  come 
out.  They  look  like  worms,  and  are  often  called 
worms. 

13.  But  most  of  the  sebaceous  glands  open  into 
the  tubes  from  which  the  hairs  grow.  They  dis- 
charge their  oil  about  the  roots  of  the  hair.  This 


THE    NAILS.  —  WHAT   THE    SKIN    IS    FOR.          17 

makes  the  hair  soft  and  glossy.  The  oil  spreads 
over  the  surface  of  the  skin  also,  and  helps  to 
keep  it  smooth  and  soft.  When  the  scalp  is  un- 
healthy, these  little  glands  do  not  work,  and  the 
hair  becomes  dry  and  brittle. 

THE    NAILS. 

14.  The  nails,  like  the  hairs,  grow  out  of  the 
skin.     They  make  the  ends  of  the  fingers  firm,  so 
that  we  can  pick  up  small  things,  and  hold  them 
better. 

15.  The  nails  are  all  the  time  growing ;  and,  if 
one  is  torn  out,  a  new  one  will  grow,  provided 
that  the  red  bed  of  skin  under  it,  from  which  it 
grows,  is  not  also  torn  away. 

The  habit  of  biting  the  nails  ought  always  to 
be  avoided.  Fingers  on  which  the  nails  are  bitten 
to  the  quick  look  badly,  and  are  less  useful  than 
others. 

WHAT   THE   SKIN    IS    FOR. 

16.  (1.)  The  skin  is  a  protection  to  the  parts 
under  it.     It  is  elastic  and  tough.     A  strong  man 
can  sometimes  split  a  board  with  his  fist  without 
breaking  the  skin. 

We  sometimes  have  to  handle  things  that  are 
poisonous.  If  our  skin  is  whole,  we  will  not  be 
hurt.  But,  if  we  have  a  scratch  or  cut  on  our 


18  PHYSIOLOGY    PRIMER. 

hands,  we  should  be  very  careful  how  we  let  any 
thing  poisonous  touch  it. 

(2.)  The  skin  keeps  the  body  warm. 

(3.)  The  skin  makes  a  delicate  and  beautiful 
covering. 

(4.)  The  skin  gives  off  waste  matters  from  the 
body. 

You  remember  about  the  sweat-glands,  —  how 
the  water  passes  from  the  blood  into  them,  and 
out  on  the  surface  of  the  body.  But  sweat  is  not 
all  water.  It  contains  also  salt  and  other  sub- 
stances which  the  body  needs  to  get  rid  of.  These 
amount  to  two  or  three  spoonfuls  in  a  day.  If  the 
skin  does  not  carry  this  off,  we  can  not  be  well. 

(5.)  The  skin  regulates  the  heat  of  the  body. 

BODILY    HEAT. 

17.  The  body  is  a  kind  of  walking  stove,  which 
is  making  heat  all  the  time.  A  number  of  cattle 
together  will  keep  a  cold  barn  warm,  and  a  num- 
ber of  people  in  a  room  will  make  it  very  hot  in 
warm  weather. 

The  food  that  we  eat  is  the  fuel,  and  the  life  in 
us  is  the  fire.  When  the  fire  is  out,  the  stove  is 
cold.  When  the  life  is  out,  the  body  is  cold.  Now, 
the  heat  that  is  made  is  kept  in  by  the  skin  and 
by  the  clothing. 


BODILY   HEAT.  19 


18.  But  suppose  we  are  too  warm.     Then  the 
skin,  instead  of  keeping  in  heat,  lets  it  out;  and 
it  does  it  in  this  way  :  — 

If  our  faces  are  hot,  and  we  wet  them,  and  let 
them  dry  in  the  air,  it  cools  them.  When  water 
Iries  off  from  any  thing,  it  always  cools  it.  If  we  are 
too  warm,  the  sweat-glands  go  to  work  actively, 
and  the  water  wells  up  fast  on  the  surface,  and 
dries  off.  This  makes  us  cooler ;  and,  when  we  are 
cool  enough,  the  sweat-glands  work  more  slowly 
again. 

19.  Some    men    are   foolish   enough   to   drink 
whisky,  when  it  is  hot,  to  make  them  cool ;  and, 
when   it  is   cold,   they  drink   it  to  make  them 
warm. 

They  might  better  trust  to  the  natural  action  of 
the  healthy  skin,  which  whisky  interferes  with. 

20.  In  cold  weather  we  eat  more  food,  and  we 
wear  thicker  clothing.     Clothing  does  not  make 
heat,  but  it  keeps  in  the  heat  we  have.     Besides 
that,  we  are  obliged  to  keep  fires  burning,  in  order 
to  be  comfortable.     We  are  not  as  independent  as 
the  animals,  whose  bodies  can  make  heat  enough 
to  endure  winter  without  fires. 

21.  The   temperature   of  the  blood  is  always 
about   100°   Fahrenheit  when   we    are  well.     It 
makes  little  difference  whether  the  air  about  us  is 


20  PHYSIOLOGY   PRIMER. 

warm  or  cold.     In  the  African  and   the   Green- 
lander  it  is  the  same. 

When  we  have  a  fever,  it  is  higher,  and  may 
reach  106°  or  107°  Fahrenheit. 

CARE   OF   THE   SKIN. 

22.  Since  the  skin  has  such  important  work  to 
do,  we  ought  to  take  good  care  of  it.     We  are  not 
likely  to  tear  our  skins,  or  burn  them,  or  wear 
holes  in  them,  —  as  we  do  with  our  clothes, — if 
we  can  help  it.     Nature  has  filled  them  full  of 
delicate  little  nerves,  which  give  us  great  pain  if 
we  do  any  such  thing.     We  are  pretty  careful  not 
to  hurt  them,  or  to  let  any  one  else  hurt  them. 
But  we  may  neglect  them. 

23.  It  is  bad  for  the  skin  to  wear  too  thick 
clothing.     It  keeps  it  wet  with  perspiration,  and 
softens  and  weakens  it. 

It  is  bad  for  the  skin  to  stay  too  much  in  hot 
rooms.  The  skin  needs  fresh  air  to  make  it  vig- 
orous. 

BATHING. 

24.  The  skin   should    be    thoroughly   washed 
often.     A  daily  bath  is  an  excellent  thing. 

Bathing  keeps  the  pores  and  the  sebaceous 
glands  open.  The  rubbing  by  which  we  dry  it 
makes  the  blood  flow  through  it,  and  makes  it  soft 


THINGS    TO    BE    AVOIDED.  21 

and  pliable.  The  cool  water  rouses  it,  and  makes 
it  active.  If  we  bathe  often,  we  shall  not  be  likely 
to  catch  cold.  We  catch  cold  by  getting  the  skin 
chilled  by  damp  air  or  water.  By  bathing  and 
rubbing,  the  skin  becomes  strong,  so  that  it  is 
not  as  easily  chilled  when  we  are  in  a  draught, 
or  wet  our  feet  People  have  been  cured  of  many 
diseases  by  simply  bathing  and  rubbing  the  skin. 
It  is  one  of  the  very  best  ways  to  prevent  disease. 
Bathing  in  salt  water  is  more  refreshing  than 
bathing  in  fresh  water.  The  salt  stimulates  the 
skin. 

THINGS   TO    BE   AVOIDED. 

25.  When  you  are  perspiring  a  good  deal,  do 
not  sit  down  on  damp  ground,  or  in  a  draught  of 
air.     It  may  give  you  a  cold  to  chill  your  heated 
skin  so  suddenly. 

For  the  same  reason,  do  not  go  into  cold  water 
when  you  are  heated  from  play.  Cool  off  first. 

Do  not  bathe  directly  after  eating. 

Never  stay  in  the  water  until  you  are  chilled 
through.  It  may  injure  you  seriously. 

EFFECTS   OF  ALCOHOL   AND    NARCOTICS. 

26.  A  clear  complexion  is  a  great  beauty.    Any 
thing  that  will  destroy  it  should  be  avoided  if  pos- 
sible.    The  use  of  alcoholic  liquors  reddens  the 


22  PHYSIOLOGY   PEIMER. 

nose,  and  often  mars  the  face  with  blotches  and 
pimples. 

27.  Tobacco-using  boys  acquire  a  sallow,  lifeless- 
looking  skin,  which  represents  the  condition  of 
4heir  whole  system. 


QUESTIONS. 

SECT.  I.  —  1.  What  parts  make  up  the  body?    Where  is  the 
thigh?  the  fore-arm? 

How  may  the  body  be  divided  into  parts  which  are  just  alike? 
What  covers  the  body  ? 

SECT.  II.  —  1.  Describe  the  skin.    What  happens  when  we  raise 
a  blister  ?  when  we  scrape  the  skin  off? 

2.  What  is  a  scar?    What  danger  in  a  large  scar? 

3.  What  should  we  take  pains  to  prevent  when  the  skin  is  de- 
stroyed in  any  part  ? 

4.  What  is  dandruff?    How  does  the  skin  wear  off?    Why  -floes 
it  not  wear  out  ? 

5.  What  is  perspiration? 

6*  What  are  the  pores  ?    How  many  of  them  are  there  ? 

7.  Describe  the  sweat-glands. 

8.  How  do  the  sweat-glands  act  ? 

9.  Where  does  the  sweat  come  from? 

10.  How  many  sweat-glands  are  there?     How  long  a  tube 
would  they  make  if  all  were  joined  in  one? 

11.  Why  has  not  man  as  much  hair  as  the  lower  animals? 
What  is  the  use  of  hair? 

Where  are  the  roots  of  the  hair? 

12.  What  is  a  sebaceous  gland?    What  does  it  give  out? 

13.  What  have  the  sebaceous  glands  to  do  with  the  hair? 

14.  What  do  the  nails  grow  from?    What  are  they  good  for? 


QUESTIONS.  23 


15.  Will  a  nail  grow  again  if  it  is  torn  off? 

16.  Uses  of  the  skin.    Name  the  first  mentioned ;  the  second; 
the  third ;  the  fourth ;  the  fifth. 

1 7.  How  is  the  body  kept  warm  ? 

18.  How  is  the  body  cooled  when  too  warm? 

19.  Is  whisky  good  to  keep  men  warm  or  cold  ? 

20.  How  do  we  keep  our  heat  in  cold  weather? 

21.  What  is  the  temperature  of  the  blood?    Is  it  the  same  ID 
all  men?    How  does  it  change  in  a  fever? 

22.  How  does  Nature  keep  us  from  injuring  our  skins? 

23.  What  is  bad  for  the  skin? 

24.  What  is  the  effect  of  bathing  the  skin?    How  do  we  catci* 
cold? 

25.  Name  some  things  to  be  avoided. 

26.  How  may  the  use  of  alcohol  affect  the  skin? 

27.  How  may  the  use  of  tobacco  affect  the  skin? 


24  PHYSIOLOGY    PRIMER. 


CHAPTER    III. 


THE    MUSCLES. 

SECT.  I.  —  1.  We  have  taken  a  general  view  of 
the  outside  of  the  body,  and  studied  its  covering. 
We  have  next  to  examine  the  parts  beneath. 

If  I  ask  you  what  we  shall  find  if  we  take  off 
the  skin  of  an  animal,  you  will  probably  answer 
flesh. 

If  I  ask  you  what  flesh  is,  you  will  tell  me  that 
it  is  a  part  of  an  animal  which  is  red  and  soft  and 
elastic,  and  that  it  is  good  to  eat. 

You  perhaps  do  not  know  that  this  flesh,  which 
is  served  up  as  roast  beef,  mutton,  and  other  meats, 
is  the  muscle  of  the  animal.  While  he  is  living, 
it  enables  him  to  move  and  work.  When  he  is 
killed,  it  is  our  food. 

2.  If  you  grasp  your  fore-arm  just  below  your 
elbow,  and  then  douoie  your  fist  tightly,  you  wil] 
feel  your  fore-arm  swelling,  and  growing  hard. 

All  boys  know  how  to  bend  the  elbow,  and  feel 
the  lump  rising  on  the  front  of  the  arm. 

It  is  muscle  that  swells  and  hardens  under  the 
skin. 


TIIE    MUSCLES. 


25 


3.  Our  flesh  is  not  all  one  mass  of  muscle,  but 
it  is  made  up  of  many  muscles  bound  together. 


Fig.  4. 

Muscles  of  the  Back. 


Muscles  are  of  different  shapes.     Some  of  them 
are  flat,  like  a  piece  of  cloth.     Flat  muscles  are 


26  PHYSIOLOGY   PEIMEE. 

spread  out  over  the  trunk  of  the  body.  Some 
of  them  are  long  and  slender.  The  sartorius  or 
tailor's  muscle,  which  is  in  the  thigh,  is  about  two 
feet  long.  Some  of  them  are  shaped  like  a  spindle 
full  of  thread.  The  smallest  muscle  in  the  body 


Fig.  5. 

1.  BICEPS  MUSCLE.    The  dotted  lines  indicate  the  changed  shape  of  the  biceps 
when  the  fore-arm  Is  drawn   up. 

is  called  the  stapedius.     It  is  in  the  ear,  and  is 
not  more  than  one-sixth  of  an  inch  long. 

4.  Most  of  the  muscles  are  attached  to  a  bone 
at  each  end.  When  they  swell  and  shorten,  they 
draw  one  of  these  bones  nearer  to  the  other. 
When  you  lay  your  hand  on  your  arm,  and  feel 
the  muscle  in  it  swell,  it  is  drawing  the  fore-arm 
toward  the  shoulder.  This  muscle,  called  the 
biceps,  is  attached  to  a  bone  of  the  shoulder  above, 
and  to  a  bone  of  the  fore-arm  below. 


WALKING.  27 


It  is  by  the  muscles  acting  in  this  way  that  we 
make  all  our  movements. 

WALKING. 

5.  For  example,  let  us  see  how  we  walk.  Stand 
with  your  feet  together.  Begin  slowly  to  walk, 
and  see  what  you  do.  First  you  lean  a  little,  so 
as  to  throw  your  weight  on  either  your  right  or 
your  left  foot.  Let  it  be  the  left  this  time.  Then 
the  muscles  of  your  thigh  contract,  and  lift  your 
right  foot  from  the  ground,  and  carry  it  forward. 
All  this  time  your  weight  is  resting  on  your  left 
foot.  When  you  have  carried  your  right  foot  far 
enough  forward,  you  let  it  come  down  on  the 
ground.  Then  both  feet  are  on  the  ground,  the 
right  being  some  distance  ahead  of  the  left.  Next 
the  muscles  of  the  calf  of  your  left  leg  shorten ; 
and  that  raises  your  left  heel  from  the  ground, 
and  throws  your  whole  body  forward  on  your 
right  foot.  Then  the  muscles  in  your  left  thigh 
contract,  and  lift  the  left  foot  clear  of  the  ground; 
and  it  swings  forward  by  its  own  weight  —  like 
a  pendulum  —  until  it  is  ahead  of  the  right  foot, 
when  it  is  planted  on  the  ground.  So  each  foot 
in  its  turn  swings  ahead  of  the  other. 

The  muscles  mentioned  are  not  the  only  ones 
engaged  in  walking.  A  great  many  muscles  take 


28 


PHYSIOLOGY    PEIMER. 


Tendon 


uscle. 


part.  These  are  the  principal  ones.  By  laying 
your  hand  on  your  thigh  or  calf,  you  can  feel 
them  harden  as  you  step. 

TENDONS. 

6.  Most  of  the  muscles  have  a 
tendon  at  one  or  both  ends.     A  ten- 
don is  a  strong,  tough  white  cord 
or  band.     It  may  be  round  or  flat ; 
and  it  does  not  stretch,  as  muscle 
does.       Any    boy   whose    parents 
kindly  let  him  have  the  drumstick 
when  there  is  chicken  for  dinner, 
can  find  the  tendons  in  it.     They 
are  not  good  to  eat,  but  they  are 
very  good  to  fasten  a  muscle  to  a 
bone. 

7.  The   largest    tendon    is    the 
tendon  of  Achilles,  the  thick  cord 
which  is  fastened  to  the  heel.     It 
is  at  the  end  of  two  big  muscles 
that    make    the   calf.       You   can 
easily  find  out  why  it  is  called  the 

tendon  of  Achilles.     The  story  is  too  long  to  tell 
here. 

The  tendons  of  the  muscles  of  the  fore-arm  can 
be  seen  and  felt  just  above  the  wrist. 


Fig.  6. 

Muscles  and  Tendons. 


TWO    KINDS    OF   MUSCLE.  29 

TWO    KINDS   OF    MUSCLE. 

8.  The  muscles  on  the  outside  of  the  body  con- 
tract when  we  will.      They  are   called  voluntary 
muscles.     But  there  are  other  muscles,  which  do 
not  obey  our  wills.     They  are  called  involuntary 
muscles.      These  are  chiefly  inside  of  the  body. 
They  are  in  the  walls  of  the  stomach  and  bowels 
and    of    the    breathing-tubes    and    blood-vessels. 
The  heart  itself  is  made  of  this  kind  of  muscle. 
These  muscles  work  of  themselves,  without  asking 
our  permission.     The  Creator  has  made  us  so  that 
we  can  move  our  bodies  as  we  please.     But  the 
heart  and  other  involuntary  muscles  he  put  in  us 
to  do  a  certain  work  by  his  direction.     We  can 
help  or  hinder  them,  but  we  can  not  control  them 
directly  by  our  wills. 

It  is  much  better  for  us  that  it  is  so.  The  work 
of  the  involuntary  muscles  is  necessary  for  the 
continuance  of  our  lives.  They  are  like  good  ser- 
vants that  do  it  for  us  without  troubling  us  to 
look  after  them. 

HOW   MUSCLE   CONTRACTS. 

9.  We  do  not  know  how  muscle  shortens  when 
we  wish  it  to.     We  know  that  it  does  so;  but  we 
can  not  explain  it. 


30  PHYSIOLOGY   PEIMER, 

EXERCISE. 

SECT.  II.  —  1.  All  parts  of  the  body  were  made 
to  be  used.  Prisoners  grow  pale  and  thin  and 
weak  for  want  of  exercise.  If  your  leg  gets  lame, 
so  that  you  can  not  use  it,  in  a  little  while  you 
will  find  it  growing  softer  and  smaller  than  the 
other  one. 

2.  The  muscles  make  nearly  half  of  the  body, 
so  they  need  a  good  deal  of  exercise.     The  plays 
which  are  natural  for  children  are  good  for  them. 
They  make  the  muscles  strong  and  active. 

3.  One  reason  why  exercise  is  good  for  the  mus- 
cles is,  that  it  makes  the  blood  flow  faster  through 
them.     If  the  blood  is  cut  off  from  a  muscle,  it 
gets  numb,  and  will  not  work.     Plenty  of  blood 
makes  it  grow. 

4.  Another  reason  is,  that,  when  we   exercise, 
we  breathe  fast,  and  get  a  good  deal  of  oxygen 
into  our  blood.     Such  blood  gives  more  life  to  the 
muscles. 

5.  If  we  wish  to  have  well  and  active  bodies, 
we  must  be  willing,  not  only  to  play,  but  also  to 
work,  with  our  muscles. 

EXPRESSION    OF    THE    FACE. 

6.  A  very  important  set  of  muscles  is  in  the 
face.     They  are  attached  to  the  skin,  and  by  their 
action  give  various  expressions. 


EFFECT    OF   ALCOHOL    AND    TOBACCO.  31 

Those  expressions  which  are  most  frequently  on 
the  face,  finally  become  fixed  there.  So  the  face 
shows  the  state  of  the  mind,  and  one  who  desires 
to  have  a  beautiful  face  must  be  careful  to  keep  a 
kind  and  happy  temper. 

THINGS   TO    BE    AVOIDED. 

7.  We  should  not  try  to  do  things  that  are  too 
hard  for  our  strength. 

Neither  should  we  try  to  keep  up  an  exercise 
until  we  are  exhausted.  By  running,  or  jumping 
rope,  too  long,  children  may  be  seriously  injured. 

EFFECT    OF  ALCOHOL    AND    TOBACCO. 

SECT.  III.  —  1.  The  tendency  of  alcohol  is  to 
cause  muscle  to  change  into  fat.  Men  who  drink 
a  good  deal  of  it  may  look  very  large  and  strong 
when  they  are  really  weak.  Their  muscles  are 
not  hard,  but  soft  and  fatty. 

Men  who  are  training  for  a  race  do  not  use  alco- 
hol and  tobacco,  because  they  know  their  muscles 
will  be  weakened  by  them. 

2.  It  is  a  fine  thing  for  a  boy  or  a  man  to  have 
strong  muscles. 

He  can  enjoy  himself,  and  help  others  better, 
for  it.  It  is  not  a  fine  or  a  manly  thing  to  have 
the  sallow  face,  and  thin  legs  and  arms,  that  are 


32  PHYSIOLOGY    PRIMER. 

likely  to  belong  to  boys  who  smoke  cigarettes  or 
cigar-stumps. 


QUESTIONS. 

SECT.  I.  —  1.  What  lies  beneath  the  skin? 
What  is  flesh? 

2.  What  swells  and  hardens  when  we  bend  our  elbows? 

3.  What  shapes  have  muscles  ?    Where  is  the  longest  muscle  in 
the  body?    Where  is  the  shortest? 

4.  What  do  muscles  do?    What  are  they  attached  to?    What  is 
the  biceps  muscle  attached  to? 

5.  Describe  the  process  of  walking. 

6.  What  is  a  tendon?    What  is  its  use? 

7.  Where  is  the  tendon  of  Achilles?    Why  is  it  so  named? 

8.  What  are  the  two  kinds  of  muscle  called? 
What  is  the  difference  between  them  ? 

Where  are  the  involuntary  muscles  chiefly  found? 

9.  Do  we  know  how  muscle  shortens  ? 

SECT.  II.  —  1.  What  happens  to  a  muscle  if  we  do  not  exercis* 
it? 

2.  How  much  of  the  body  is  muscle? 

3.  Give  a  reason  why  exercise  is  good  for  the  muscles. 

4.  Another  reason. 

5.  What  must  we  do  to  have  well  and  active  bodies? 

6.  What  gives  expression  to  the  face? 
How  may  we  cultivate  beauty  of  face  ? 

7.  In  exercising,  what  caution  is  to  be  observed? 

SECT.  III.  — 1.  What  is  the  effect  of  alcohol  on  muscle?    Do 
athletes  in  training  use  it? 

2.  Does  using  tobacco  make  a  boy  manly,  or  unmanly? 


OF  THE 

UNIVERSITY 


Fig.  7. 
The  Arterial  System. 


THE    HEART    AND    BLOOD-VESSELS.  35 


CHAPTER  IV. 


THE    HEART   AND    BLOOD-VESSELS. 

SECT.  I.  —  1.  If  you  cut  yourself,  or  even  prick 
yourself  with  a  fine  needle,  blood  will  flow. 

In  examining  the  flesh  of  an  animal,  after  taking 
off  the  skin,  we  find  it  to  be  full  of  blood. 

In  almost  every  part,  even  in  the  bones,  there  is 
blood. 

If  we  look  very  carefully  at  the  flesh  with  a 
microscope,  we  find  that  the  blood  is  not  in  it  in 
the  same  way  that  water  is  in  a  wet  sponge.  It  is 
filled  with  little  tubes,  —  some  of  them  so  small 
that  you  can  not  see  them  with  the  naked  eye, 
and  some  larger, — and  the  blood  is  contained  in 
these  tubes.  They  are  so  close  together,  that,  if 
you  make  never  so  small  a  cut,  you  are  sure  to 
cut  some  of  them,  and  let  the  blood  out.  These 
tubes  are  called  blood-vessels. 

2.  The  blood-vessels    are  arteries,  capillaries: 
and  veins. 

3.  The  arteries  are  all,  except  one,  branches  of 
a  large  tube  that  comes  out  of  the  heart.     This 
tube,  which  is  called  the  aorta,  runs  up  a  little 


36  PHYSIOLOGY    PRIMER. 

way,  and  gives  branches  to  the  head  and  arms,  and 
then  goes  down  by  the  backbone,  giving  branches 
to  the  trunk  of  the  body  and  the  parts  inside. 
Finally,  it  divides  into  two  tubes,  that  run  down 
trough  the  legs  to  the  feet. 

4.  The  branches  that  come  off  from  this  great 
tube  keep  dividing  and  dividing,  until,  finally,  the 
branches   become   so  small   that  they  are   called 
capillaries,  which  means  "  like  hairs" 

If  these   capillaries  were   laid   side  by  side,  it 
would   take  3,000  of  them  to   cover  a  space  an 

inch  wide. 

There  are  a  great  many  of 
them,  and  they  make  a  net- 
work as  close  as  any  spider's 
web  that  you  see  in  the  grass 
on  a  summer  morning.  They 
FI8>  8m  are  thick  in  almost  every 

Capillary  Plexus  magnified.  _      ,         ,         , 

part  of  the  body. 

5.  The  vessels,  after  dividing  into  capillaries, 
soon  unite  to  form  veins.  These  veins  join  together, 
to  form  larger  ones,  just  as  streams  join,  to  form 
larger  streams  and  rivers.     Finally,  all  are  united 
in  two   great  veins  which  open   into   the   heart. 
The  blood-vessels,  which  lie  just  beneath  the  skin, 
and  which  swell  and  look  purple  when  you  press 
them,  are  veins. 


THE    HEART. 


37 


THE    HEART. 

6.  The  heart  is  in  the  breast,  and  lies  toward 
the  left  side.  If  you  begin  at  your  collar-bone, 
on  the  left  side,  and  count  the  ribs  downward,  you 
will  find  the  point  of  the  heart  beating  just  under 
the  fifth  rib. 

It  is  shaped  like  a  pear.     It  is  made  of  muscle. 


Pulmonary  artery. 


Aorta. 


Vena  cava  superior. 


Pulmonary  veins.  -::!'.. 

Right  auricle 

Tricuspid  valve 

Vena  cava  inferior 


Eight  ventricle.    /•' 


.Pulmonary  artery. 
-/Pulmonary  veir 


Left  auricle. 

'— Mitral  valve. 


Left  ventricle. 


Aorta. 


Fig.   0. 
The  Chambers  of  the  Heart. 


It  is  hollow,  and  is  divided  in  the  middle  into  two 
halves,  which  are  entirely  separate  from  each  other. 
Each  half  is  divided  into  two  chambers,  which  are 
connected  by  an  opening.  The  two  chambers  on 
the  right  side  are  called  the  right  auricle  and  the 
right  ventricle.  The  two  chambers  on  the  left  side 
are  called  the  left  auricle  and  the  left  ventricle. 


38  PHYSIOLOGY    PRIMER. 

7.  1  Imagine  yourself  small  enough  to  get  inside 
the  heart,  and  take  a  journey  through  the  blood- 
vessels, to  find  out  more  about  them.  Start  in  the 
right  auricle.  If  you  look  about  you,  you  will  find 
that  it  has  thin  walls,  and  has  a  lining  smooth  as 
glass.  You  will  see  three  large  openings  in  the 
walls.  Two  of  them  are  the  openings  of  the  two 
great  veins  that  empty  into  the  heart.  The  third 
is  about  an  inch  wide,  and  you  pass  through  it 
into  the  right  ventricle.  This  has  thicker  walls 
than  the  auricle.  There  is  only  one  opening  to 
let  you  out  of  it;  and  you  pass  through  this,  and 
find  yourself  in  a  great  tube  with  the  same  smooth 
lining  that  the  cavities  had.  You  are  out  of  the 
heart,  and  are  in  the  pulmonary  artery. 

Traveling  through  this  artery,  you  soon  come 
to  a  place  where  it  divides  into  two,  —  one  going 
to  the  right  lung,  the  other  to  the  left.  You  may 
take  which  you  choose.  As  you  enter  the  lung, 
you  find  your  passage-way  constantly  dividing 
into  smaller  ways.  You  find,  too,  that  the  walls 
of  the  tubes  are  growing  thinner,  but  the  same 
glossy  lining  continues.  Finally,  you  get  into  a 
passage  so  narrow,  that,  if  you  are  more  than  3^  of 
an  inch  in  size,  you  can  not  get  through  it  without 

1  I  am  indebted,  for  the  suggestion  of  the  illustration  following,  to 
Professor  Foster,  Science  Primer,  Physiology,  p.  52. 


THE    HEART. 


39 


squeezing.      This    is   a   capillary.      You   are   glad 

when  the  passage  grows  a  little  larger,  and  you 

find  yourself  in  a  vein.     This  leads   you  into  a 

larger  vein,  and  this  into  a  still  larger  one,  until 

you  are  in  one  of  the  pulmonary  veins ;  and  from 

that  you   plunge  into  another 

cavity.     You  have  reached  the 

heart  again,  and  are  in  the  left 

auricle.       This,  which   is   very 

much   like    the    right    auricle, 

opens    into    the    left    ventricle. 

Pausing   in   this   cavity  before 

you  leave  the  heart  once  more, 

you  will  perceive  that  its  walls 

are  much  thicker  than  those  of 

the  other  cavities.     Taking  the 

only  opening    out    of    it,  you  F|g  I0 

enter   another   great   tube,  the   CIRCULATION   IN  MAN.- 

.  °  a.  Right    auricle.       b.  Right 

aOrta.  ThlS      IS      Of     abOUt      the         ventricle,    c.  Pulmonary  ar- 

tery,    d.  Capillaries  of  the 

same  size  as  the  pulmonary  ar-     lungs.  «.  pulmonary  veins. 

,  .  ,,  ,    .     ,  f.  Left  auricle,    y.  Left  ven- 

tery,  but  its  walls  are  thicker     tncie.   A.  Aorta,  f.  oaPu- 

d»  laries.    k.  Vein. 

stronger.     As  you  pass  on, 

you  notice  that  there  are  many  large  tubes  open- 
ing out  of  it.  But  you  keep  the  main  channel 
until  at  length  you  reach  a  point  where  it  divides. 
Taking  either  of  the  two  divisions,  you  move  on 
down  into  the  thigh,  the  leg,  and  the  foot.  All 


40  PHYSIOLOGY    PRIMER. 

the  while  your  tube  has  been  growing  smaller  as 
it  gave  off  branches.  Soon  you  find  yourself  again 
in  a  capillary.  But  it  is  only  a  fraction  of  an  inch 
long,  and  you  are  quickly  through  it,  and  are  in 
a  vein.  Passing  up  by  the  same  course  by  which 
you  came,  the  vein  grows  larger  and  larger  as 
branches  join  it.  You  traverse  the  leg  and  thigh, 
and,  when  you  reach  the  back  again,  you  are  in 
one  of  the  two  great  veins  which  open  into  the 
right  auricle  of  the  heart.  There  you  find  yourself 
resting  after  your  long  journey. 

8.  As  you  rest,  you  think  about  two  things  that 
you  have  noticed. 

(1.)  You  noticed  that  you  saw  no  openings  out 
of  the  blood-vessels.  There  were  a  great  many  dif- 
ferent ways  that  you  might  take,  but  they  all  con- 
nected, like  the  paths  in  a  park;  and,  though  you 
might  wander  about  a  good  while,  you  would 
always  get  back  at  last  to  the  heart. 

(2.)  You  noticed,  that,  at  many  points  in  your 
journey,  you  passed  through  open  gates,  and  that 
they  always  opened  in  the  direction  in  which  you 
were  going.  This  would  not  have  been  so,  if,  when 
you  started  in  the  right  auricle,  you  had  gone 
directly  into  a  vein,  and  so  through  the  veins  into 
the  capillaries,  and  then  through  the  arteries  back 
to  the  heart.  If  you  had  gone  in  that  direction, 


THE  HEART, 


41 


you  would  hav^  found  that  the  gates  opened  to- 
ward you,  and  that  if  you  happened  to  strike 
against  them,  or  if  there  had  been  a  crowd  trying 
to  get  through  with  you,  you  would  have  closed 
them  against  yourself. 

This  shows  you  that  it  was  intended  that  the 
blood  should  flow  in  the  direction  in  which 
you  went,  —  through  the  arteries  first,  and  back 
through  the  veins.  It  could  not  flow  the  other 
way,  because  it  would  close  the  gates  against  it- 
self. 

These  gates  are  called  valves.  They  are  made 
of  thin  membrane,  and  are  more  like  curtains 
than  gates ;  but  they  are  tough  and  strong,  and  fit 
so  that  they  close  the  way  perfectly. 

They  work  like  the  valves  in  a  pump,  which 
allow  the  water  to  come  up,  but 
shut  when  the  water  settles  back. 

The  valve  which  closes  the 
opening  between  the  right  auricle 
and  ventricle  is  called  the  tri- 
cuspid  valve.  The  valves  at  the 
entrance  of  the  pulmonary  artery 
and  the  aorta  are  the  semilunar 
valves.  The  valve  between  the 
left  auricle  and  ventricle  is  the  mitral  valve.  Be- 
sides these,  there  are  valves  all  along  the  veins, 


Fig.    II. 

Semilunar  Valves  partly 
closed. 


42  PHYSIOLOGY    PRIMER. 

though  there  are  none  in  the  arteries  except  the 
semilunar  valves  just  mentioned. 

ACTION    OF    THE    HEART. 

9.  If  you  have  a  pretty  good  idea  of  the  heart 
and  blood-vessels  from  your  journey,  you  can  now 
learn  what  they  do. 

We  know,  to  begin  with,  that  the  heart  and 
blood-vessels  are  full  of  blood.  We  know,  also, 
that  the  blood  is  always  moving  through  them,  as 
rivers  and  streams  are  always  flowing.  We  can 
even  see  it  move  in  the  blood-vessels  which  are  in 
the  thin  web  of  a  frog's  foot,  if  we  look  at  them 
with  a  microscope.  We  know,  too,  that  it  is 
always  flowing  in  the  direction  which  you  took 
on  your  journey, —  from  the  heart  through  the 
arteries  and  capillaries,  ^nd  back  to  the  heart 
through  the  veins.  It  is  easy  to  find  this  out 
when  an  artery  or  vein  is  cut  off.  We  can  see 
which  way  the  stream  is  running.  We  know,  be- 
sides, that  it  could  not  flow  the  other  way,  on 
account  of  the  valves. 

1C.  The  heart  and  blood-vessels  are  not  like 
lead  pipes,  that  simply  let  the  water  flow  through 
them.  The  heart  is  a  live  pump.  It  works  itself. 
The  blood-vessels  stretch  and  contract,  and  so  help 
the  heart  to  keep  the  blood  moving  through  them. 


ACTION  OF  THE  HEAET.  43 

11.  If  you  lay  your  ear  against  any  one's  breast, 
you  can  hear  and  feel  the  heart  beat.  It  begins  to 
beat  almost  at  the  beginning  of  life,  and  keeps 
on  until  we  die.  The  only  rest  it  gets  is  a  very 
short  rest  between  the  beats.  But,  as  there  are  a 
great  many  beats  in  a  day,  of  course  there  are 
a  great  many  of  these  short  rests.  If  they  were 
all  put  together,  it  would  make  one  long  rest  of 
eight  hours  in  a  day.  But  no  other  muscle  does 
sixteen  hours  of  constant  work  in  twenty-four. 

±2.  The  heart  beats  very  fast  in  a  baby,  —  as 
many  as  a  hundred  and  twenty  times  in  a  minute 
if  he  is  less  than  a  year  old.  In  a  grown  man,  it 
beats  about  seventy  times  in  a  minute.  When  we 
are  excited,  it  beats  faster  and  harder,  sometimes 
so  hard  that  it  gives  us  distress.  When  we  exer- 
cise, it  beats  fast. 

When  we  are  well,  we  do  not  think  any  thing 
about  our  hearts,  or  even  feel  that  they  are  in  our 
breasts. 

13.  What  makes  the  heart  beat,  and  what  is  it 
doing  ? 

You  remember  that  the  heart  is  made  of  muscle. 
You  remember,  too,  that  muscle  can  shorten  and 
thicken.  If  we  could  look  through  the  breast 
at  the  heart,  we  would  see,  that,  at  every  beat,  it 
thickens  and  hardens,  just  as  the  biceps  does  when 


44  PHYSIOLOGY    PRIMER. 

you  bend  your  elbow.  At  the  same  time,  it  jumps 
a  little,  and  its  point  hits  the  inside  of  the  breast. 
Then  it  softens  again  for  an  instant  before  the  next 
beat. 

14.  Double    your    fist    loosely,   and    suddenly 
tighten  it,  and  you  will  make  a  motion  somewhat 
like  a  heart-beat.     Your  fist,  too,  is  of  about  the 
same  size  as  your  heart.     Now,  if  you  put  your 
fist  in  a  basin  of  water,  and  close  and  unclose  it, 
the  water  will  squirt  out  as  you  tighten  your  fist. 
That  shows  you   what  the   heart  does   when   it 
beats.     It  is  full  of  blood  ;  and,  when  it  contracts, 
it  squirts  the  blood  out  into  the  pulmonary  artery 
and  the  aorta. 

15.  A  common  rubber  syringe  will  show  you 
how  the  heart  works.     The  bulb  of  the  syringe  is 
the   heart.     The   tube   that   goes   into   the   water 
represents   the   great  veins,   and   the   other  tube 
represents  the  aorta.     Every  squeeze  you  give  the 
bulb  is  like  a  beat  of  the  heart. 

16.  You  know,  that,  in  such  a  syringe,  the  water 
goes  only  one  way.     If  you  put  the  wrong  tube  in 
the  water,  it  will  not  go.     That  is  because  there 
are  valves  in  the  tubes  that  keep  the  water  from 
going  backward.     Just  so  the  blood  goes  only  one 
way  from  the   heart.     The  valves   keep   it  from 
going  the  other  way. 


THE  PULSE.  45 


17.  If  you  should  fill  the  bulb  and  the  tubes 
with  water,  and  then  join  the  ends  of  the  two 
tubes   together  so   that   the  water  could   not  get 
out,  but  would    keep   going   around   and  around 
through  the  tubes  and  the  bulb  as  you  squeezed, 
you  would  have  something  a  good  deal  like  the 
circulation  of  the  blood. 

THE    PULSE. 

18.  When   you   are   sick,  the  doctor  puts   his 
finger  on   your  wrist  to  feel  your  pulse.     Under 
the  end  of  his  finger  something  beats,  just  as  the 
heart  beats  against  the  chest,  and  almost  at  the 
same  time. 

It  is  a  small  artery  that  he  feels.  When  the 
heart  beats,  it  forces  blood  into  the  arteries.  They 
were  nearly  full  before,  but  they  can  stretch  like 
rubber.  As  the  blood  is  forced  in,  they  stretch 
and  swell  and  rise  up  under  the  finger.  A  pulse 
can  be  felt  in  several  places.  If  you  look  sharply, 
you  can  see  a  pulse  in  the  neck  often.  It  is  the 
carotid  artery  that  beats  there.  The  pulse  in  the 
wrist  is  generally  chosen,  because  it  is  the  most 
convenient. 

19.  By  feeling  the  pulse,  we  may  learn,  among 
other  things,  — 

(1.)  How  fast  the   heart  beats.      If  we  have  a 


46  PHYSIOLOGY    PRIMER. 

fever,  it  beats  too  fast.     In  some  sicknesses  it  beats 
too  slowly. 

(2.)  How  strongly  it  beats.  If  the  heart  is  strong, 
the  pulse  will  be  strong.  If  the  heart  is  weak, 
the  pulse  will  be  weak. 

20.  The  blood  flies  quite  swiftly  through  the 
large  arteries.     It  moves  more  slowly  through  the 
capillaries.     If  an  artery  is  cut,  it  will  spurt  out 
in  jets.     If  capillaries   only  are  cut,  it  will  ooze 
out  in  drops.     If  a  vein  is  cut,  it  will  flow  out  in 
a  steady  stream. 

EFFECTS   OF  ALCOHOL   AND   TOBACCO. 

21.  When  we  see  a  man  whipping  a  good  horse 
that  is  going  fast  enough,  we  feel  angry.     Now, 
the  heart  is  like  a  willing  horse.     When  it  is  mak- 
ing its  seventy  beats  in  a  minute,  it  is  going  fast 
enough.     It  is  unnecessary  and  foolish  to  use  any 
thing  that  will  act  as  a  whip  does  on  a  horse,  and 
make  it  beat  faster.     That  is  just   what  alcohol 
does.     If  it  is  beating  seventy  times  in  a  minute, 
a  little  alcohol  will  often  make  it  beat  seventy-four 
or  seventy-five  times  in  a  minute.     Four  or  five 
extra  beats  in  a  minute  make  a  great  many  extra 
beats  in  a  day.     And  all  these  extra  beats  are  labor 
lost.     They  are  using  the  strength,  without  doing 
a  particle  of  good. 


EFFECTS  OF  ALCOHOL  AND   TOBACCO.  47 

22.  Alcohol,   when  used  habitually,  often   in- 
jures the  heart  and  blood-vessels. 

The  heart  it  injures  by  changing  its  fibers  partly 
into  fat.  The  blood-vessels  it  injures  by  making 
them  hard  and  brittle. 

Of  course,  a  fatty  heart  can  not  be  as  strong 
as  if  it  were  all  muscle,  and  it  can  not  do  its 
work  as  well.  It  is  liable  to  stretch  and  wear  out 
before  its  time. 

23.  When  the  blood-vessels  are  brittle,  a  man  is 
in  danger  of  apoplexy. 

Apoplexy  is  a  disease  caused  by  the  breaking  of 
a  blood-vessel  in  the  brain.  The  person  who  has 
it  becomes  paralyzed  in  part  or  all  of  the  body. 
He  may  become  insensible,  and  die  within  a  few 
days ;  or  he  may  get  better,  but  remain  paralyzed. 
He  very  seldom  gets  entirely  well. 

Young  persons  do  not  often  have  apoplexy, 
unless  their  blood-vessels  are  injured.  The  habit 
of  drinking  prepares  the  blood-vessels,  and  often 
brings  on  the  shock. 

24.  The  beats  of  a  healthy  heart  are  regular 
and  steady,  like  the  working  of  a  steam-engine. 
When   the  heart  is  out  of  order,  its  beating  is 
irregular  and  unsteady.    One  of  the  causes  of  such 
a  condition  is 'tobacco. 

When  a  doctor  says  that  Mr.  A  or  Mr.  B  has  a 


48  PHYSIOLOGY    PRIMER. 

"  smoker's  heart,"  he  means  that  he  has  got  his 
heart  into  this  unsteady  state  by  smoking  or  chew- 
ing tobacco. 

QUESTIONS. 

SECT.  I.  —  1.  How  is  the  blood  held  in  the  tissues? 

2.  What  are  the  three  kinds  of  blood-vessels? 

3.  What  is  the  aorta? 

4.  What  are  the  capillaries? 

5.  What  are  the  veins?    Where  can  we  see  the  veins? 

6.  Where  is  the  heart  situated?    What  is  its  shape?    What  is 
it  made  of  ?    How  is  it  divided  ? 

7.  Describe  a  journey  through  the  blood-vessels,  starting  in 
the  heart. 

8»  What  two  things  might  you  notice  on  such  a  journey? 
What  are  the  gates  you  pass?  What  are  they  like  ?  What  is  the 
name  of  the  gate  between  the  right  auricle  and  ventricle?  What 
is  the  name  of  the  gates  at  the  beginning  of  the  aorta  and  of  the 
pulmonary  artery  ?  What  is  the  name  of  the  gate  between  the  left 
auricle  and  ventricle? 

9.  How  do  we  know  that  the  blood  is  always  moving  in  the 
blood-vessels  ?    In  which  direction  does  it  flow  ? 

10.  What  machine  does  the  heart  resemblej?. 

11.  What  can  you  hear  and  feel  if  you  lay  your  ear  against  any 
one's  breast?    Does  the  heart  get  any  rest?    How  much? 

12.  How  fast  does  the  heart  beat?    What  makes  it  beat  faster  ? 
Do  we  feel  our  hearts  when  we  are  well? 

13.  What  makes  the  heart  beat?    Describe  the  process. 

14.  How  can  you  illustrate  a  heart-beat?    What  is  the  size  of 
the  heart  ? 

What  does  the  heart  do  when  it  beats  ? 

15.  16.  Give  another  illustration  of  the  action  of  the  heart. 
17.  How  can  you  illustrate  the  circulation  of  the  blood? 


QUESTIONS.  49 


18.  What  is  the  pulse?    What  causes  the  beating  which  you 
can  sometimes  see  in  the  neck  ? 

19.  What  can  be  learned  by  feeling  the  pulse? 

20.  How  does  the  blood  come  when  an  artery  is  cut?  when 
capillaries  are  cut?  when  a  vein  is  cut? 

21.  What  is  the  effect  of  alcohol  on  the  heart?    Is  it  wise  to 
whip  up  a  healthy  heart? 

22.  What  changes  can  alcohol  make  in  the  substance  of  the 
heart?  what  changes  in  the  blood-vessels? 

23.  What  disease  threatens  a  man  with  brittle  arteries?    What 
is  apoplexy?    Do  young  persons  often  have  it?    What  may  cause 
it  in  a  young  person? 

24.  What  is  meant  by  the  name  "  smoker's  heart "  ? 


50  PHYSIOLOGY    PRIMER. 


CHAPTER    V. 


THE     BLOOD.—  WEAR    AND    REPAIR.  - 
THE     LYMPHATICS. 

SECT.  I.  —  1.  A  man  has  in  his  body  about  six 
quarts  of  blood,  —  not  quite  an  ordinary  wooden 
pail  full.  It  is  the  most  precious  of  all  fluids. 
For  "  the  blood  is  the  life,"  as  says  Scripture. 
That  is  the  reason  why  some  people  turn  sick 
and  faint  when  they  see  blood  flow.  It  is  like 
seeing  the  life  go  out.  A  man  can  not  lose  more 
than  half  of  his  blood,  and  live.  The  loss  of 
much  less  than  half  might  be  fatal. 

2.  Blood  is  a  red  fluid  so  thick  that  you  can  not 
see  through  it. 

If  you  put  a  cut  finger  in  your  mouth,  you  find 
that  blood  tastes  salty,  and  has  a  smooth  feeling 
to  the  tongue.  When  fresh,  it  is  warm. 

3.  When  any  one  is  cut,  the  blood  at  first  runs 
fast.     In  a  little  while,  if  the  cut  is  not  a  very 
large  one,  it  runs  more  slowly,  and  begins  to  grow 
thick;  and  soon  it  stops  altogether,  even  if  you 
have  not  done  much  to  stop  it.     If  any  of  it  has 
dropped  on  the  floor,  it  will  turn  in  a  few  minutes 
to  a  ielly-like  mass. 


THE  BLOOD.  51 


4.  If  you  should  go  to  the  butcher's,  and  get  a 
bowl  full  of  fresh  blood,  and  let  it  stand  fifteen 
minutes,  you  would  have  a  bowl  full  of  this  same 
jelly-like  substance.     This  is  called  dotted  blood. 

5.  Fresh  blood  always  dots  when  it  flows  out 
of  the  blood-vessels.     It  is  well  for  us  that  it  does 
so.     If  it  did  not  clot,  it  would  keep  on  until  you 
bled  to  death.     It  would  not  be  safe  to  have  a 
tooth  pulled.     As  it  is,  the  wound  is  soon  plugged 
with  clotted  blood. 

6.  But  why   does    it    not   clot    in  the    blood- 
vessels ?     That  we  can  not  tell.     We  know  that  it 
does  not,  and  we  know  that  it  does  clot  in  the  air. 
We  know,  too,  that  it  clots  more  quickly  when  it 
is  running  slowly. 

If  you  press  your  finger  on  a  cut,  or  tie  a 
handkerchief  over  it,  it  will  check  the  flow  of 
the  blood,  and  give  it  a  chance  to  clot.  Then, 
when  you  take  your  finger  or  your  bandage  off, 
it  will  not  start  again. 

7.  Sometimes  the  blood  flows  so  fast  that  you 
can   not  stop   it  by  pressing  on   the  wound,  or 
bandaging  it.     This  happens  when  a  large  blood 
vessel  is  cut.     If  it  is  an  artery  that  is  bleeding, 
you   should  tie  a  handkerchief  or  a  cord  tight 
around  the  limb,  above  the  wound;   below  the 
wound,  if  it  is  a.  vein. 


52  PHYSIOLOGY    PRIMER. 

8.  How  can  you  tell  whether  it  is  an  artery  or 
a  vein  that  is  bleeding  ? 

(1.)  Blood  flows  in  spurts  from  an  artery.  It 
flows  in  a  steady  stream  from  a  vein. 

(2.)  Blood  from  an  artery  is  bright  scarlet  in 
color.  Blood  from  a  vein  is  darker,  nearly  purple. 

If  you  can  not  tell  by  these  indications,  tie  the 
handkerchief  around  the  limb  above  the  wound ; 
and,  if  that  is  not  sufficient,  tie  one  below  also. 

These  bandages  can  be  kept  on  for  an  hour  or 
two,  if  necessary,  until  a  physician  arrives. 

9.  If  you  look  at  a  drop  of  blood  with  a  micro- 

scope, you  will  see  a  watery  fluid 

fin      \J^ 

_  .         **      with   very   many    little    round 

bodies  floating  in  it. 


"j§    l| 


watery  fluid  is  called  the 
plasma.     The  round  bodies  are 
called  the  corpuscles.     Some  of 
Red  corpuscles  of  Human  these   corpuscles  are  white,  but 

Blood  (4OO  diameters).  r>     ,  -i  7 

most  of  them  are  red. 

The  red  corpuscles  make  rosy  cheeks  and  cherry 
lips.  Sometimes  there  are  not  so  many  of  them 
as  there  should  be,  or  they  are  pale  in  color. 
This  makes  pale  faces  and  white  lips. 

1C.  If  we  lay  aside  our  microscope,  and  ex- 
amine blood  by  the  aid  of  chemistry,  we  shall 
find  that  — 


WEAR  AND  REPAIR.  53 

(1.)  Nearly  four-fifths  of  the  blood  is  water. 

(2.)  The  blood  contains  many  substances,  which 
come  from  the  food  we  eat,  and  are  for  the  nour- 
ishment of  the  body. 

(5.)  The  blood  contains  waste  matters,  which 
come  from  the  wear  of  the  body. 

(4.)  The  blood  contains  oxygen  from  the  air. 

The  blood,  then,  is  the  carrier  of  nourishment, 
waste,  oxygen. 

WEAR    AND    REPAIR. 

11.  Now  we  can  begin  to  see  what  the  blood 
is  for,  and  why  the  blood-vessels  carry  it  through 
every  nook  and  corner  of  the  body,  and  why  the 
heart  keeps  pumping  day  and  night. 

The  body,  like  every  thing  else  in  the  world,  is 
all  the  time  wearing  out.  Work  and  play,  walk- 
ing, talking,  breathing,  even  thinking,  wear  it. 

The  little  worn-out  particles  are  of  no  further 
use.  They  must  be  cleared  away.  So  they  are 
drawn  into  the  capillaries,  and  washed  along  into 
the  veins,  and,  finally,  they  are  cast  out  in  one  of 
three  ways. 

{the  lungs, 
the  skin, 
the  kidneys. 

12.  The  body  must  be  repaired  as  fast  as  it 
wears,  or  else  it  would  soon  be  worn  out.      So 


64  PHYSIOLOGY    PRIMER. 

the  blood  must  take  up  the  nourishment  that  is 
digested,  and  carry  it  around  to  all  the  little 
hungry  particles  of  flesh  and  bone  and  nerve,  to 
make  up  to  them  for  what  it  takes  away. 

13.  Every   little   particle  of   the    body   wants 
oxygen.     It  can  not  live  without   it.     The  blood 
takes  it  in  from  the  lungs,  and  carries  it  about 
for  distribution.     The  red  corpuscles  are  the  boats 
in  which  the  oxygen  rides.      It  gets  on  in  the 
lungs,  and  gets  off  in  the  different  parts. 

14.  So  the  blood  is  constantly  changing.      It 
takes  up  something  here,  and  gives  out  something 
there.     It  may  be  compared  to  a  train  of  freight- 
cars,  which  goes  through  the  country  loading  and 
unloading  at  every  station.     As  the  people  at  each 
station  take  out  what  they  need,  and  send  away 
what  they  do  not  want,  so  each  particle  in  the 
body  takes  out  from  the  blood  what  it  needs,  and 
gives  up  what  it  does  not  want. 

15.  You  have  learned  that  there  are  no  open- 
ings out  of  the  blood-vessels.     How,  then,  can  the 
nourishment  from  the  blood  get  to  the  flesh,  and 
how  can  the  waste  matters  from  the  flesh  get  into 
the  blood? 

You  remember  that  the  arteries,  as  they  divide 
and  grow  smaller,  have  thinner  and  thinner  walls. 
The  capillaries  have  the  thinnest  walls  of  all. 


THE  LYMPHATICS. 


56 


They  are  so  thin  and  delicate,  that  nourishment 

dissolved    in    the    blood    can 

soak   out   of  them,  and   dis- 

solved waste  matters  can  soak 

into  them.     Oxygen,  too,  can 

easily  pass  through.    The  cap- 

illaries are  so  near   together, 

that  almost  every  particle  in 

the  body  is  bathed  in  the  fluid 

that  soaks  through  them. 

THE    LYMPHATICS. 

16.  A  cistern  or  tank  for 
water  generally  has  an  over- 
flow pipe.  There  is  a  pipe  to 
bring  in  the  water,  and  a  pump 
to  draw  it  out,  and,  besides,  a 
pipe  near  the  top,  through 
which  the  water  can  run  off 
if  it  gets  too  full.  The  body 
has  a  set  of  overflow  pipes. 
They  are  called  lymphatics. 
These  tubes  do  not  begin  at 
the  heart,  as  the  blood-vessels 
do.  They  begin  among  the  Superficlal 
capillaries  all  through  the 
body.  They  are  at  first  more  delicate  even  than 


56  PHYSIOLOGY    PRIMER. 

the  capillaries.  They  join  together,  and  grow 
larger,  just  as  the  veins  do,  and  run  toward 
the  heart.  They  do  not  empty  into  the  heart, 
but  into  the  great  veins  near  the  heart.  So  all 
the  fluid  that  they  take  up  gets  finally  into  the 
blood. 

17.  All  along  the  course  of  the  lymphatics  are 
little  knots  as  large  as  a  pea  or  a  bean.     These  are 
called  the  lymphatic  glands.     In  the  neck  they 
often  swell,  and  are  then  sometimes  painful. 

FAINTING. 

18.  No  part  of  the  body  can   live  long  if  its 
supply  of  blood  is  cut  off.     If  a  string  were  tied 
around  your  finger  tightly  enough  to   stop   the 
flow  of  blood,  and  kept  on,  it  would  die.     If  the 
heart  for  any  cause   suddenly  weakens,  the  head 
swims,  the  sense  of  sight  and  other  senses  fail,  the 
consciousness   is  lost.      This  is  a  fainting-fit.      It 
means  that  the  brain  is  not  getting  its  usual  sup- 
ply of  blood.     This  weakening  of  the  heart  may 
be  caused  by  fright,  or  bad  air,  or  pain.     Any  one 
who  is  faint  ought  to  be  laid  down  flat,  because  in 
that  position  the  blood  can  flow  to  the  brain  more 
easily;  and  he  ought  to  have  fresh  air,  because 
that  makes  the  blood  better,  and  stimulates  the 
heart. 


OF  THB 

EFFECTS  OF  ALCOHOL  AND   TOB\CCO.-^        57 

UFOR] 
PURE   BLOOD. 

19.  Since  the  blood  has  so  much  to  do  with 
the  life  of  the  body,  it  is  very  important  to  keep 
it  pure. 

We  may  keep  the  blood  pure,  — 

(1.)  By  exercise.  The  blood  flows  faster  when, 
we  exercise,  and  keeps  purer,  just  as  a  running 
stream  is  purer  than  a  stagnant  pool. 

(2.)  By  bathing.  This  keeps  the  skin  active, 
and  an  active  skin  carries  off  impurities  from 
the  blood. 

(3.)  By  moderation  in  eating.  When  we  eat  too 
much,  the  blood  is  loaded  with  more  nourishment 
than  it  can  dispose  of. 

(4.)  By  avoiding  unwholesome  foods.  Somethings 
are  unwholesome,  even  if  you  take  but  little  of 
them.  Unripe  fruit  or  decayed  fruit  is  so. 

Some  things  are  wholesome  if  you  take  but 
little,  but  very  unwholesome  if  you  eat  a  great 
deal.  Candy  and  rich  cake,  and  sweetmeats  or 
pickles,  are  of  this  class. 

EFFECTS    OF    ALCOHOL    AND    TOBACCO. 

20.  Alcohol    is    taken    into    the    blood,    and 
mingles  with  the   other  substances   dissolved   in 
it.     It  is  not  just  like  any  of  them.     It  does  not 
belong  anywhere.      It   is   carried  swiftly  around 


58  PHYSIOLOGY    PRIMER. 

in  the  current;  and,  wherever  it  goes,  it  stirs  up 
commotion.  It  whips  the  heart,  and  excites  the 
nerves.  It  goes  to  every  station  on  the  road ;  and, 
if  there  is  more  than  a  small  quantity  of  it,  they 
all  refuse  to  take  it  in :  and,  finally,  it  is  thrown 
out  as  useless  by  way  of  the  lungs  or  skin  or 
kidneys. 

Alcohol  is  an  impurity  in  the  blood  itself,  and 
it  causes  other  impurities  by  injuring  the  stomach. 

A  moderate  use  of  alcohol  often  makes  people 
crave  too  much  rich  and  stimulating  food.  A 
great  deal  of  alcohol  takes  away  the  appetite 
altogether. 

21.  The  nicotine  which  is  contained  in  tobacco 
is  taken  into  the  blood  through  the  lungs,  the 
mouth,  and  stomach.  By  the  blood,  it  is  carried 
to  every  part  of  the  body.  Its  effects  do  not 
appear  immediately.  Often  it  seems  as  if  it  were 
having  no  effect.  In  other  cases,  we  can  clearly 
see  that  it  is  poisoning  the  whole  system. 


QUESTIONS. 

SECT.  I.  —  1.  How  much  blood  has  a  man  in  his  body?  HOT? 
much  can  he  lose,  and  yet  live?  Why  do  we  feel  faint  at  the  sight 
of  blood? 

2.  What  is  the  color,  taste,  and  feeling  of  blood? 

3.  What  happens  when  we  are  wounded? 


QUESTIONS.  59 


4.  What  is  clotted  blood? 

5.  What  good  purpose  does  clotting  serve? 

6.  Does  blood  clot  in  the  blood-vessels?    How  can  you  help  it 
to  clot  in  a  wound? 

7.  What  can  you  do  when   you  can  not  stop  the  blood  by 
bandaging  the  wound? 

8.  How  can  you  tell  whether  blood  comes  from  an  artery  or 
iS  vein? 

9.  How  does  a  drop  of  blood  look  under  a  microscope?    What 
is  the  watery  part  called?     What  are  the  round  bodies  called? 
What  is  the  color  of  the  round  bodies?    What  makes  rosy  cheeks? 

10.  What  is  the  chief  part  of  the  blood? 

What  three  things  does  the  blood  contain?    Where  does  each 
one  of  these  things  come  from? 

11.  Does  the  body  wear?     What  becomes  of   the  worn-out 
particles  ? 

By  what  three  ways  does  waste  matter  go  out  of  the  body? 

12.  How  is  the  body  repaired? 

13.  How  is  the  oxygen  carried  in  the  blood? 

14.  Is  the  blood  ahvays  the  same? 
How  is  it  like  a  freight-train  ? 

15.  How  does  nourishment  get  out  of  the  blood,  and  waste 
matter  get  in? 

16.  What  are  the  lymphatics ?    What  do  they  do? 

17.  What  are  the  lymphatic  glands  ? 

18.  What  is  constantly  needful  for  the  life  of  the  body?     What 
is  a  fainting-fit?     What  should  be  done  with  a  person  who  has 
fainted?    Why? 

19.  Why  is  it  important  to  keep  the  blood  pure?    How  may 
\ve  keep  it  pure  ? 

Is  unripe  fruit  ever  wholesome? 
Are  candy  and  cake  ever  wholesome? 

20.  What  does  alcohol  do  in  the  blood?    What  becomes  of  i* 
at  last? 

How  does  alcohol  affect  the  appetite  ? 

21.  How  does  nicotine  enter  the  blood?    What  is  its  effect? 


60  PHYSIOLOGY    PRIMER. 


CHAPTER    VI. 


FOOD    AND    WATER  —  STIMULANTS   AND 
NARCOTICS. 

SECT.  I.  —  1.  The  blood  carries  nourishment  to 
every  particle  of  the  body.  Let  us  inquire  now 
what  this  nourishment  is,  and  where  it  comes 
from.  It  is  contained  in  food  and  water.  And 
all  our  food  and  water  come  from,  the  earth  and 
the  air.  Think  of  this,  and  see  if  you  can  remem- 
ber any  kind  of  food  that  does  not  come  from  the 
earth  or  air. 

2.  Perhaps  you  will  say,  beef  does  not.     But  it 
does.     For  the  ox  lives  on  grass  and  grain,  and 
grass  and  grain  come  from  the  earth  and  air.     So 
with  all  kinds  of  meat.     The  food  of  all  animals 
comes  at  last  from  plants. 

3.  The  food  of  plants  is  the  air  and  the  min- 
erals which  are  dissolved  in  the  earth. 

Animals  can  not  live  on  air  and  minerals. 
Plants  can.  That  is  one  great  difference  between 
animals  and  plants.  And  one  great  business  of 
the  plants  is  to  take  air  and  minerals  into  them- 
selves, and  make  them  into  food  for  animals. 


ANIMAL  FOOD.  61 


Probably  every  plant  is  food  for  some  kind  of 
animal,  big  or  little. 

4.  If  you  were  lost  in  a  forest,  you  would  very 
likely  starve  to  death.     All  around  you  the  birds 
would  be  full  of  life,  and  the  rabbits  and  squirrels 
and  foxes  would  be  growing  fat.     But,  unless  you 
could  manage  to  catch  some  of  these  animals,  you 
would  have  nothing  to  eat.      What  is  food  for  a 
bird  or  a  squirrel  or  a  horse,  is  not  food  for  you. 

But  there  are  some  plants  that  you  can  eat.  It 
is  the  business  of  farmers  to  raise  these  plants. 
Farmers  also  take  care  of  the  animals  that  are 
food  for  men. 

ANIMAL    FOOD. 

5.  The   most   nourishing   animal   food   is    beef. 
Lamb   and   mutton   and  fowls   come  next.     Many 
people  eat  pork  more  than  any  other  meat.     It  is 
not  so  digestible  or  healthful  as  beef  and  mutton. 
It  ought  always  to  be  well  cooked. 

Raw  ham  and  raw  sausages  are  dangerous. 
They  often  contain  a  little  worm,  called  the  tri- 
china, which  causes  a  severe  disease  in  those  who 
eat  them.  The  trichina  is  killed  by  thorough 
cooking. 

6.  Fish  is  a  light  and  digestible  food.     But  it  is 
much  better  on  the  seacoast,  or  near  the  places 
where  it  is  caught,  than  elsewhere.     It  spoils  by 


62  PHYSIOLOGY    PEIMEE. 

being  kept,  sooner  than  beef  or  mutton,  and  is 
likely  to  lose  its  fine  flavor  when  it  is  carried  far. 

7.  Oysters  are  a  favorite  food  with  very  many. 
They  are  easily  digested  and  nutritious.     It  is  a 
good  rule  to  eat  them  only  in  the  months  that 
have  an  r  in  them. 

8.  Eggs   contain  a  great  deal  of  nourishment, 
and  are  easily  eaten. 

9.  There   is  no  one  food  as  valuable  as  milk. 
Infants  live  on  it  for  the  first  year  or  two,  and 
sick  people  can  live  a  long  time  on  it  when  they 
can  not  take  any  thing  else. 

VEGETABLE    FOOD. 

1C.  The  principal  grains  used  as  food  are  wheat, 
rice,  corn,  oats,  rye,  and  barley. 

Many  millions  of  the  human  family  live  on 
rice.  It  is  the  chief  food  in  China,  India,  and 
some  other  countries. 

In  Europe  and  America,  wheat  is  the  most  val- 
ued grain.  Corn  contains  the  most  oil,  and  is  a 
richer  food  than  the  others.  Oatmeal  contains 
much  bran,  and  is  a  coarse  article  of  diet;  but 
it  is  wholesome  for  most  people. 

11.  No  vegetable  is  used  more  generally  in  civ- 
ilized countries  than  the  potato.  It  is  a  native  of 
North  America,  and  was  introduced  into  Europe 


COOKING.  63 


three  hundred  years  ago.  Since  that  time  it  has 
become  the  chief  food  of  great  numbers  of  people. 
No  other  vegetable  is  so  light  and  delicate. 

1 2.  Dried  pease  and  beans  are  hard  to  digest,  be- 
cause they  contain  so  much  solid  matter.     But,  for 
this  very  reason,  they  are  good  for  armies,  or  for 
men  who  are  exploring  or  hunting,  who  have  to 
carry  a  good  deal  of  nourishment  in  small  bulk. 

13.  Green   garden  vegetables    are    healthful,   on 
account  of  the  juices  which  they  contain. 

COOKING. 

14.  Animals   eat  their   food   raw.     Men    cook 
most  of  theirs.     Cooking  makes  food  more  digest- 
ible, and  it  gives  good  flavors.     It  makes  a  great 
difference  with  our  appetites  whether  our  food  is 
well  cooked,  or  not.     There  is  no  art  which  has 
more  to  do  with  health  and  comfort  than  cookery. 
It  is  therefore  worth  learning. 

15.  Bread  is  so  large  a  part  of  our  diet,  that  it 
is  worthy  of  more  attention  than  any  other  article. 
Good  bread  is  light  and  sweet.     In  order  to  have  it 
light  and  sweet,  you  must  have,  — 

(1.)  Good  flour. 
(2.)  Good  yeast. 
(3.)  Good  mixing. 
(4.)  Good  judgment. 


64  PHYSIOLOGY    PRIMER. 

The  good  judgment  must  be  gained  by  experi- 
ence, and  is  used  in  deciding  when  the  mass  is 
warm  enough,  when  it  has  risen  long  enough, 
when  the  oven  is  hot  enough,  and  when  the  bread 
should  be  taken  out. 

Sour  bread  makes  sour  tempers. 

Hot  bread  is  not  so  light  and  digestible  generally 
as  cold  bread. 

16.  Besides  bread,  pastry  and  cake  are  made  of 
grain.     These  contain  lard  or  butter,  and  sugar. 
This  makes  them  rich,  and  pleasant  to  the  taste. 
A  moderate  quantity  of  them  does  no  harm ;  but, 
if  we  eat  heartily  of  such  food,  we  are  giving  the 
stomach  too  much  work  to  do. 

MINERAL    FOOD. 

17.  The  only  mineral  that  we  eat  by  itself  is 
salt.     It  is  a  great  hardship  to  be  deprived  of  it. 
It  helps  digestion,  and  is  very  necessary  in  the 
body.     Some   animals   need   it  as  much  as  men. 
The  cattle  on  the  Western  plains  will  go  a  long 
distance  to  find  a  salt-spring. 

But  it  is  poison  to  fowls. 

Other  mineral  substances  are  contained  in  many 
articles  of  food. 

WATER. 

18.  When  we  remember  that  about  eight-tenths 


WATER.  65 


of  the  blood  is  water,  and  that  about  seven-tenths  of 
the  whole  body  is  water,  and  that  we  are  losing 
water  constantly  through  the  lungs  and  the  skin 
and  the  kidneys,  we  can  see  why  it  is  so  necessary 
to  us.  We  can  bear  to  go  without  food  better  than 
to  be  deprived  of  water. 

19.  Good  drinking-water  is  clear  and  transpar- 
ent, and  it  has  no  taste  or  odor.     But  even  water 
with  no  taste  or  odor  is  sometimes  bad.    There  are 
many  poisonous  substances  which  may  be  dissolved 
in  water,  which  will  not  give  it  any  smell  or  taste 
or  color.     People  often  drink  bad  water  without 
knowing  that  it  is  bad. 

It  is  important  to  be  careful  of  the  drinking- 
water,  to  see  to  it  that  nothing  harmful  gets 
into  it. 

20.  Water  that  runs  through  lead  pipes  may 
have  a  little  lead  dissolved   in  it.     You   can   not 
taste  it  or  smell  it  or  see  it.     It  does  not  make  you 
sick  at  once.     But  by  and  by  you  find  that  a  dis- 
ease is  upon  you.     Even  if  you  stop  drinking  the 
water,  it  may  be  a  long  time  before  you  are  well. 

Intoxicating  drinks  sometimes  act  just  like 
water  with  lead  in  it.  They  do  not  seem  to  do 
any  harm  at  first.  The  drinker  is  well,  and  they 
make  him  feel  better.  But  by  and  by  he  knows 
that  they  are  injuring  him.  Then,  when  he  tries 


66  PHYSIOLOGY    PRIMER. 

to  stop,  he  finds  that  he  has  got  a  habit  of  taking 
them  which  he  can  not  easily  break. 

It  is  not  safe  to  use  lead  pipes  unless  we  know 
that  the  water  we  use  does  not  act  on  them.  It 
may  be  necessary  to  ask  the  opinion  of  a  chemist. 

21.  Water  may  have  foul  matters   in  it  from 
sewers   and  drains.     This   sometimes   happens   to 
the  drinking-water  of  cities.     You  would  suppose, 
that,  in  the  country,  the  water  would  always  be 
pure.     But,  in  many  a  farmhouse,  they  are  drink- 
ing water  that  has  in  it  slops  from  the  sink,  or 
drainings  from  the  barnyard.    So  they  get  typhoid 
fevers,  and  other  diseases. 

22.  The  well  should  never  be  within  thirty  feet 
of  a  pigpen  or  barnyard,  or  other  foul  spot.      It 
should  never  be  where  the  ground  slopes  down  to 
it  from  any  such  place. 

When  it  is  necessary  to  use  water  that  is  not 
pure,  it  should  be  boiled  and  filtered.  This  makes 
it  safer. 

HABITS. 

23.  People  of  different  countries  prefer  different 
foods.     In  Ireland,  the  potato  holds  the  first  place; 
in  Scotland,  oatmeal ;  in  India  and  China,  rice. 
In  hot  climates,  a  very  little  food  is  sufficient.     An 
Arab  can  travel  all  day  with  no  other  food  than  a 
handful  of  grain ;  but  an  Esquimau,  after  fasting, 


STIMULANTS  AND  NARCOTICS.  67 

will  eat  several  pounds  of  clear  fat  at  a  meal.  In 
some  countries,  almost  nothing  is  eaten  before 
noon.  In  cold  northern  latitudes,  people  want  a 
hearty  breakfast. 

24.  So  people  in  the  same  country  differ  in 
their  habits.  One  prefers  one  kind  of  food,  and 
another  another  kind.  One  dines  at  noon,  another 
at  night.  It  is  not  necessary  that  all  should  have 
the  same  habits,  but  there  are  some  rules  which 
all  should  observe. 

We  should  remember  that  we  eat  to  live,  and  do 
not  live  to  eat. 

We  should  eat  nothing  that  we  know  to  be  harmful 
to  us,  even  if  it  be  very  pleasant  to  the  taste. 

We  should  not  eat  too  much. 

STIMULANTS    AND    NARCOTICS. 

SECT.  II. — 1.  Did  you  ever  get  too  much  pepper 
in  your  mouth  ?  Did  it  make  your  tongue  smart, 
and  set  you  to  coughing,  and  make  your  eyes 
water?  If  so,  you  know  what  a  stimulant  is.  To 
stimulate  means  to  excite,  to  stir  up,  to  irritate. 
A  stimulant  is  any  thing  that  excites  and  stirs  up 
and  irritates.  The  pepper  irritated  your  tongue 
and  throat,  and  stirred  you  up. 

2.  Mustard  is  another  stimulant.  Horse-radish, 
spices  of  all  kinds,  and  many  herbs,  are  stimulants. 


68  PHYSIOLOGY    PRIMER. 

We  want  only  a  little  of  them  with  our  food,  —  so 
little,  that  they  are  not  worth  any  thing  for  the 
nourishment  they  contain.  But  they  give  food  a 
flavor,  and  arouse  the  appetite. 

In  this  way  pepper  and  mustard  may  not  be 
harmful  if  used  moderately. 

3.  But,  after  all,  "Hunger  is  the  best  sauce." 
What  we  really  want,  when  we  sit  down  to  eat,  is 
the  nourishment  that  is  in  the  plain  food,  and  not 
the  pleasure  that  the  taste  of  spices  gives  us.     One 
whose  health  is  good  does  not  often  need  to  have 
his  appetite  stimulated.      By  spiced  and  highly 
seasoned  food,  we  are  easily  tempted  to  eat  too 
much. 

4.  Such  food  is  not  as  well  digested.     The  good 
stomach,  which  is  faithfully  doing  its  work,  does 
not  like  to  be  stirred  up  by  too  much  spice,  any 
more  than  your  tongue  likes  too  much  pepper ;  so 
it  feels  badly,  and  can  not  act  as  well. 

5.  By  indulgence  in  "any  kind  of  stimulants,  the 
desire  for  them  is  likely  to  increase.     We  may  learn 
to  bear  larger  and  larger  quantities,  until  all  food 
that  is  not  very  highly  flavored  seems  flat  to  us. 

TEA    AND    COFFEE. 

6.  Tea  and  coffee  are  stimulating  drinks.     Tea  is 
made  from  the  leaf  of  a  plant  which  is  cultivated 


OPIUM.  69 


in  China  and  Japan,  and  coffee  from  a  berry  which 
is  brought  from  Arabia,  and  other  warm  countries. 
Like  the  food-stimulants  just  spoken  of,  they  do 
not  afford  much  nourishment.  They  are  used  for 
f.he  warmth  and  comfort  which  they  give. 

7.  Probably  you  are  not  allowed  to  have  any. 
This  is  right.  Grown  persons  are  not  injured  by 
them  so  much  as  children,  whose  bodies  are  more 
delicate,  would  be.  But  grown  people  are  some- 
times injured  very  much  by  them.  They  hurt 
their  stomachs,  and  give  them  headaches,  and 
make  them  nervous  and  fretful  and  unhappy. 
Some  people  ought  never  to  use  tea  and  coffee. 
Every  one  ought  to  be  careful,  and  not  take  too 

much. 

OPIUM. 

8.  When  a  person   is   sick   and   in   pain,   the 
doctor  sometimes  gives  him  a  dose   of  opium  to 
ease  him  and  make  him  sleep.     It  may  be  in  a 
powder,  or  it  may  be  in  a  liquid  form.     Indeed, 
most  of  the  medicines  which  stop  pain    contain 
it.     They  should  not  be  taken,  therefore,  without 
a  doctor's  order.     For  opium  is  a  very  dangerous 
drug  indeed. 

9.  There   are   many   other   drugs,  which,  like 
opium,  can  make  a  person  quiet  or  drowsy  or  un- 
conscious.    We  call  them  narcotics.     Some  things 


70  PHYSIOLOGY    PRIMER. 

are  both  stimulants  and  narcotics.  If  a  man  takes 
a  single  glass  of  wine,  it  is  a  stimulant.  It  excites 
him.  If  he  takes  a  great  many,  and  becomes 
drunk  and  stupid,  it  is  a  narcotic. 

1C.  Opium  is  a  blessing  when  properly  used  by 
the  physician.  But,  when  improperly  used,  it  is 
a  terrible  evil.  Those  who  take  it  a  good  while 
come  to  depend  on  it.  It  is  even  harder  to  give  it 
up  than  to  give  up  drinking.  People  use  it,  not 
to  relieve  pain  only,  but  because  it  gives  pleasure. 
They  may  not  know,  when  they  begin,  that  it  can 
harm  them.  At  first  they  only  feel  the  pleasant 
effects.  But  by  and  by  they  find  that  it  is  making 
them  sick  and  weak  in  body  and  mind.  They 
become  good  for  nothing.  Since  there  is  this 
danger  in  it,  it  ought  never  to  be  taken  except 
when  the  doctor  orders  it. 

11.  Opium  is  the  juice  of  the  poppy.  This 
plant  grows  in  our  gardens,  and  has  a  beautiful 
flower;  but  most  of  the  opium  is  brought  from 
the  East,  where  fields  of  poppies  are  cultivated. 
Laudanum  is  opium  in  a  liquid  form.  Morphine  is 
a  white  powder  which  is  made  from  opium.  It 
has  the  same  effects,  but  it  does  not  take  so  much 
of  it  to  produce  them. 


TOBACCO.  71 


TOBACCO. 

12.  Tobacco  is  the  leaf  of  a  plant  which  was 
found  in  this  country  when  it  was  discovered  by 
Europeans.     The  Indians  taught  the  new-comers 
the  use  of  it.     After  being  thoroughly  dried,  it  is 
smoked  and  chewed  and  snuffed.     A  great  many 
men  use  it,  and  some  boys.     They  do  it  because 
they  like  its  effects.     They  say  it  makes  them  feel 
better,  and  helps  them  to  do  their  work. 

13.  Some  men  who  use  tobacco  do  not  seem  to 
be  injured  by  it.     They  are  healthy  and  strong, 
and  live  to  be  old.     Others  are  injured  very  much. 
Sometimes  they  do  not  know  that  it  is  hurting 
them.     Sometimes  they  know  it,  but  can  not  give 
it  up. 

The  first  time  it  is  used,  it  makes  the  user 
deathly  sick.  Nature  rebels  against  it.  After  a 
time,  it  does  not  cause  sickness,  but  gives  pleasure. 

14.  But,  while  it  is  giving  pleasure,  it  may  be 
doing  harm  in  several  ways,  — 

(1.)  By  weakening  the  stomach. 

(2.)  By  making  the  throat  sore.  Smokers  often 
have  sore  throat.  Cancer  in  the  throat  or  mouth 
is  at  times  occasioned  by  smoking. 

(5.)  By  disturbing  the  heart.  It  makes  it  irreg- 
ular and  weak. 


72  PHYSIOLOGY   PRIMER. 

(4.)  By  making  the  nerves  unsteady. 

15.  Tobacco  is  especially  bad  for  boys.     It  may 
stop  the  body  and  mind  from  growing,  and  make 
them  feeble  and  unhealthy  in  every  part. 

ALCOHOLIC    DRINKS. 

16.  Wines  are  made  of  the  juice  of  grapes  or 
berries.     Beer,  ale,  porter,  and  whisky  are  made  from 
grain.     Brandy  is  made  from  wine  and  cider  and 
some  other  liquors.     Rum  is  made  from  sugar-cane 
or  molasses.     All   these   drinks   contain   alcohol, 
and  it  is  for  the  alcohol  in  them  that  they  are 
used. 

17.  Alcohol    looks    like  water.     It    burns    the 
mouth  like  fire  if  it  is  taken  clear.     Brandy  is 
about  half  alcohol.     Wine  is  from   one-tenth  to 
one-fifth  alcohol. 

18.  Many  men  spend  more  money  to  get  alco- 
holic drinks  than  they  spend  for  food  or  clothes 
or  any  thing  else.     Why  do  they  want  them  so 
much? 

You  have  already  learned,  that,  when  you  take 
any  stimulant  for  a  while,  you  are  likely  to  get 
fond  of  it,  and  to  want  more  and  more  of  it.  This 
is  especially  so  with  alcoholic  drinks.  The  appe- 
tite for  them  often  keeps  growing,  until  it  is 
stronger  than  any  other  desire.  A  moderate 


IVERSITY 


I    -  £*  XV  ERE 

QUESTIONS.  \  73 

^^J!  CALIFOR' 


drinker  is  always  in  some  danger  of  becoming 
a  drunkard,  and  a  drunkard  will  give  up  every 
thing  for  liquor. 

19.  All  stimulants  have  power  to  do  harm. 
But  no  other  one  is  so  enticing  and  so  deadly 
as  alcohol.  It  can  change  a  man  into  some- 
thing worse  than  a  beast.  It  can  take  away  hir 
property  and  his  home.  It  can  destroy  his  char- 
acter. 

It  makes  more  people  poor  and  unhappy  and 
wicked  than  any  other  cause. 


QUESTIONS. 

SECT.  I.  —  1.  What  is  our  nourishment  contained  in?    Where 
does  it  all  come  from? 

2.  From  what  does  the  food  of  all  animals  come? 

3.  What  is  the  food  of  plants  ?    What  great  difference  is  there 
between  plants  and  animals?     What  service  do  plants  render  to 
animals  ? 

4.  Can  all  animals  live  on  the  same  food?    From  whom  do  we 
get  our  food? 

5.  What  is  the  most  nourishing  animal  food?    What  comes 
next?    What  caution  should  be  observed  in  eating  pork? 

6.  What  caution  should  be  observed  in  buying  fish? 

7.  In  what  months  are  oysters  best? 

9.  Which  is  the  most  valuable  food? 

10.  Name  the  principal  grains  used  as  food. 
What  is  the  chief  food  in  China  and  India  ? 

What  grain  is  most  valued  in  Europe  and  America? 

11.  What  vegetable  stands  first,  in  usefulness? 


74  PHYSIOLOGY   PRIMER. 

12.  For  what  purpose  are  dried  pease  and  beans  very  valuable? 

14.  Is  good  cooking  important? 

15.  What  is  necessary  for  making  good  bread? 

16.  What  is  the  difference  between  bread  and  cake  and  pastry? 
Are  cake  and  pastry  wholesome? 

17.  What  mineral  do  we  eat  with  our  food?    Do  we  eat  any 
Other  minerals  in  our  food  ? 

18.  How  much  of  the  blood  is  water?    How  much  of  the  body 
is  water?    Why  must  we  keep  drinking  it  ? 

19.  Describe    good   drinking-water.     Is   all  water   good  that 
looks  and  seems  good? 

20.  What  mineral  sometimes  gets  into  water?    How  are  intoxi- 
cating drinks  like  poisoned  water? 

What  should  we  be  sure  of  if  we  drink  water  that  comes 
through  lead  pipes?    How  can  we  be  sure  of  it? 

21.  What  injurious  substances  that  are  not  minerals  get  into 
water?    What  is  a  result  of  drinking  such  water? 

22.  What  is  the  rule  about  the  position  of  the  well?    How  can 
we  make  bad  water  safer? 

23.  Do  all  countries  have  the  same  habits  of  eating? 

24.  Do  people  in  the  same  country  have  the  same  habits  of 
eating?    Is  it  important  that  they  should? 

What  rules  ought  all  to  remember? 

SECT.  IT.  —  1.  What  is  a  stimulant? 

2.  What  is  the  use  of  stimulants? 

3.  What  is  the  chief  object  of  eating  ?    Do  stimulants  contain 
much  nourishment? 

4.  What  is  the  harm  of  food  stimulants? 

5.  What  is  the  danger  of  indulgence  in  them  ? 

6.  What  is  tea?    What  is  coffee?    What  are  they  used  for? 

7.  Are  tea  and  coffee  good  for  children?    Are  they  always  good 
for  grown  people? 

8.  What  is  the  effect  of  opium? 

9.  What  is  a  narcotic? 


QUESTIONS.  75 


10.  How  does  opium  do  harm  ?    Is  it  safe  to  use  it? 

11.  What  is  opium?  laudanum?  morphine? 

12.  What  is  tobacco?     Why  do  men  use  it? 

13.  What  are  its  effects? 

14.  How  may  it  do  harm  ? 

15.  Who  are  most  injured  by  tobacco? 

16.  Name   some   alcoholic   drinks,  and  state  what  they  are 
of. 

17.  What  does  alcohol  look  like?    How  much  alcohol  is  there 
in  brandy  ?    How  much  in  wine  ? 

18.  Why  do  men  spend  so  much  money  for  alcoholic  drinks? 

19.  What  does  alcohol  do? 


76  PHYSIOLOGY    PRIMER. 


CHAPTER    VII. 


DIGESTION.  —ABSORPTION. 

SECT.  I.  —  1.  Let  us  suppose  ourselves  to  be 
examining  the  body  of  a  dead  animal.  We  have 
studied  the  skin,  and  have  removed  it.  We  have 
studied  the  muscles  (or  flesh)  which  lie  beneath. 
With  the  aid  of  a  microscope  we  have  studied 
the  blood  which  flows  as  we  cut  the  flesh.  We 
will  next  cut  through  into  the  inside,  and  see 
what  we  find  there. 

2.  We  find,  first,  that  the  inside  of  the  trunk 
is  divided  into  two  parts  by  a  thin  partition,  that 
extends  across  from  the  breast-bone  to  the  back- 
bone.    This  partition  is  called  the  diaphragm.     It 
is  made  of  muscle,  and  can  move  up  and  down. 
The  part  above  the  diaphragm  is  called  the  thorax, 
or  chest.     The  part  below  is  called  the  abdomen, 
or  belly. 

3.  The  things  that  we  notice  in  the  chest  are, 
two  lungs,  a  heart,  and  a  soft  fleshy  tube  which 
runs  through  it  from  top  to  bottom.     This  tube 
is  the  oesophagus,  or  gullet. 

4.  In  the  abdomen  we  see   the  liver,  the  pan- 


DIGESTION.  77 


creas,  the  spleen,  the  kidneys,  the  stomach,  and 
the  intestines,  or  bowels. 

5.  If  we  follow  the  soft  tube  —  the  gullet  —  that 
we  noticed  in  the  chest,  upwards,  we  find  that  it 
opens  into  the  throat,  and  the  throat  opens  into 
the  mouth.     If  we  follow  it  downwards,  we  find 
that  it  goes  through  a  hole  in  the  diaphragm,  and 
then  it  opens  into  one  end  of  the  stomach.     If 
we  follow  on  to  the  other  end  of  the  stomach,  we 
find  that  the  stomach  opens  into  the  bowels.     The 
bowels  are  coiled  up  in  the  abdomen,  and  end  at 
the  lower  end  of  the  trunk. 

6.  This  long  tube,  which   begins   at  the   lips, 
and    extends    through    the   trunk,   is   called   the 
alimentary  canal.      Aliment  is  nourishment.     The 
alimentary  canal  is  the   canal  -in  which  nourish- 
ment is  made  fit  to  be  taken  into  the  blood. 

7.  The  alimentary  canal  is  to  the  body  what  the 
kitchen  is  to  the  house.     Food,  as  it  comes  from 
the  butcher  and  the  grocer,  is  first  carried  to  the 
kitchen.      There   it   is   cut   up   and   ground    and 
cooked ;    and    finally   it    comes    to    us    in    nice, 
tempting    dishes,   to  satisfy  the    hunger  of   the 
family. 

So,  in  the  alimentary  canal,  the  food  we  eat  is 
cut  up,  and  the  nourishing  part  is  separated  from 
that  which  is  not  nourishing,  and  is  softened  to  a 


78 


PHYSIOLOGY   PRIMER. 


liquid,  and  changed  so  that  it  can  be  taken  into 
the  blood,  and  carried  to  all  parts  of  the  body. 
We  call  this  digestion. 

8.  This  canal  is  very  important,  and  we  must 
study  it  further. 

The  alimentary  canal   is   from   twenty-five  to 


Fig.   14. 

1.  The  Heart.    2.  The  Lungs.    3.  The  Diaphragm.    4.  The  Liver.    6.  The  Gall -Blew 
der.    6.  The  Stomach.    7.  The  Bowels. 

thirty  feet  long  in  a  man.  Of  course,  in  order 
to  get  such  a  long  tube  into  the  trunk,  which  is 
only  about  two  feet  long,  part  of  it  must  be  rolled 


DIGESTION. 


79 


up  in  a  coil.     The  coil  is  the  part  of  the  tube  that 
we  call  the  bowels. 

9.  The  lips  are  the  gates  which  close  the  en- 
trance to  the  canal.  Behind  these  gates  is  the  first 
cavity,  the  mouth.  Liquid  food  does  not  stay  in 
the  mouth,  but  passes  directly  through  it.  Solid 
food  must  be  chewed  before  it  can  go  on. 

ID.  A  baby  when  he  is  born  has  no  teeth.  But 
by  the  time  he  is  six  or  seven  months  old  they 
begin  to  come.  The  lower  front  teeth  are  the  first 
to  peep  out.  At  two  years  of  age  he  will  have 
twenty  teeth.  This  is  his 
first  set,  called  milk  teeth 
or  baby  teeth.  At  about 
five  years  of  age  he  be- 
gins to  lose  these,  and 
new  ones  take  their 
places.  The  new  ones 
keep  coming;  and  the 
last,  which  are  called  Flg-  I5< 

The  Lower  Teeth. 

wisdom  teeth,  may  not  ap- 
pear before  twenty-five  or  thirty  years  of  age.     A 
grown  person  has  thirty-two  teeth,  —  twelve  more 
than  a  child. 

11.  The  front  teeth  are  flat  and  sharp,  like 
chisels.  They  are  for  cutting.  Two  on  each 
side  —  the  eye-tooth  and  the  stomach-tooth  —  are 


80  PHYSIOLOGY    PRIMER. 

pointed    for  holding  on  to    things.      The    back 
teeth  have  broad  ends  for  grinding. 

12.  Each  tooth  has  one  or  more  roots,  which  fit 
in  a   socket  in   the  jaw-bone. 

Enamel...-. ^BflfJIfJfei    The    surface    of   the    tooth   is 

Dentine       -t^w^Bf^    enamel,   which    is   the    hardest 
Central  mg    substance  in  the  body.     In  the 


center  of  the  tooth  is  a  canal 
which  contains  little  blood- 
vessels and  nerves. 

13.  Teeth  are  liable  to  de- 
Fig.  i6.  When  they  do  so,  they 

Back  Tooth  sawed  In  two.  * 

are  sensitive  and  painful;  and 
finally  they  crumble  away  entirely.  If  we  lose 
one  of  our  first  teeth,  it  is  not  much  of  a  loss; 
for  a  new  one  will  soon  grow.  If  we  lose  a  second 
tooth,  the  dentist  must  make  us  another,  or  we 
must  go  without. 

14.  People  do  not  look  as  well  when  their 
teeth  are  gone;  and,  besides,  they  can  not  chew 
their  food  as  well. 

It  is  important,  therefore,  to  take  good  care  of 
the  teeth. 

We  must  not  bite  nuts  or  other  hard  things 
with  them.  If  they  are  broken  or  chipped,  they 
can  not  be  restored. 

We  must  keep  them  clean.      They  should  be 


DIGESTION.  81 


well  brushed  every  day.     Food  left  between  the 
teeth  injures  them. 

If  they  begin  to  decay,  they  should  be  taken 
care  of  immediately  by  a  dentist.  He  can  often 
save  them. 

15.  When  you  bite  any  thing,  your  lower  jaw 
moves  down  and  up.     When  you  chew  any  thing, 
it  moves  from  side  to  side,  as  well  as  down  and 
up,  so  that  the  food  is  ground  between  your  back 
teeth. 

16.  The  tongue  is  made  of  muscle.     Some  of 
the  fibers  run  lengthwise,  some   crosswise,  some 
up  and  down.     It  can  lengthen  and  thicken,  and 
move  in  every  possible  direction. 

17.  Now,  suppose  you  have  bitten  off  a  piece 
of  bread.      Immediately  your  jaw   moves   down 
and  up  and  sidewise.     Your  tongue  and  cheeks 
keep  the  morsel  all  the  time  between  your  teeth, 
sometimes  shifting  it  from  one  side  of  the  mouth 
to  the  other  ;  and  so  it  is  cut  and  ground  into  fine 
bits. 

18.  While   you   are   chewing,   your  mouth    is 
moist.     As  soon  as  you  begin,  —  sometimes  before 
you  begin,  when  you  are  thinking  of  nice  food, 
—  your  mouth  waters.     This  water  is  the  saliva. 
It  comes  from  six  lumps,  which  are  called  the 
salivary  glands.      Two   of  them   areust^jander 


OF  THE 

mvTTTTT-vr-j  r 


82 


PHYSIOLOGY   PRIMER. 


the  ears.  When  we  have  mumps,  these  swell  up, 
and  are  sore.  Four  of  them  are  under  the  floor 
of  the  mouth. 

It  has  been  found,  by  examining  these  glands 
with  the  microscope,  that  they 
are  made  of  bunches  of  very 
small  tubes,  with  little  sacs  on 
the  ends  of  them.  If  you  should 
take  clusters  of  cherries  or  of 
grapes,  and  press  them  together, 
you  would  have  a  mass  that 
would  be  a  little  like  a  salivary 
gland.  The  cherries  or  grapes 
would  represent  the  sacs,  and 
their  stems  would  be  like  the  tubes.  The  little 
tubes  join  to  form  larger  tubes,  which  are  called 
ducts.  The  ducts  open  into  the  mouth.  Blood- 
vessels enter  the  gland,  and  divide,  and  spread  like 
a  network  among  the  tubes  and  ducts.  Saliva  is 
made  from  the  blood,  and,  filling  the  sacs,  pours 
out  through  the  tubes  and  ducts  into  the  mouth. 

19.  Your  mouthful  of  bread,  while  it  is  being 
cut  up  and  ground,  is  being  moistened  with  saliva. 
When  you  are  ready  to  swallow  it,  it  is  a  soft  pulp. 
If  you  are  in  a  hurry,  you  may  manage  to 
swallow  food  that  is  not  thoroughly  chewed,  and 
mixed  with  saliva.  This  gives  the  stomach  more 


Fig.    17. 

Part  of  a  Salivary  Gland 
(magnified). 


DIGESTION.  83 


work  to  do.     Sometimes  it  makes  it  ache.     So  we 
should  be  sure  and  take  time  enough. 

20.  When   we   swallow,  the   tongue   forces  the 
morsel  of  food  into  the  throat,  and  the  muscles 
of  the  throat    close   around   it,   and    squeeze    it 
down   into   the  gullet.      Then   the   walls   of  the 
gullet,  which  are  muscle,  contract  behind  it,  and 
squeeze  it  down  into  the  stomach.     If  you  look 
at  a  horse  when  he  is  drinking,  you  can  see  the 
swallows  of  water  passing  one  after  another  along 
his  neck. 

21.  The  stomach  is  a  part  of  the  alimentary 
canal  which  is  larger  than  the  rest.     It  is  a  pouch 
in  which  the  food  stays  some  time,  and  is  changed 
a  good  deal.     In  a  man  it  is  about  twelve  inches 
long,  and  three  or  four  inches  wide.     It  lies  just 
under  the  heart.     When  it  is  full,  it  presses  up 
against  the  heart  and  lungs ;  and  that  is  the  reason 
why  we  are  short  of  breath  if  we  run  just  after 
dinner. 

22.  The  wall  of  the  stomach  is  partly  muscle. 
It  has  a  pink  lining,  like  the  lining  of  the  mouth. 
This  lining  is  full  of  little  pits  shaped  like  the 
finger  of  a  glove.     They  are  the  stomach-glands. 
They  make  the  gastric  juice  from  the  blood,  and 
the  gastric  juice  digests  a  part  of  the  food. 

23.  As  soon  as  the  morsel  which  is  swallowed 


84  PHYSIOLOGY    PRIMER. 

drops  into  the  stomach,  the  blood  comes  to  its 
lining,  and  makes  it  redden,  just  as  your  face 
reddens  when  you  blush.  Then  the  stomach- 
glands  make  gastric  juice  quickly.  At  the  same 


-- (Esophagus. 


Pylorus. 

: 


Stomach. 


Bowel-— 


Fig.  18. 

Section  of  the   Stomach. 


time,  the  walls  of  the  stomach  contract,  and  squeeze 
the  food,  as  if  you  should  put  some  pudding  in  a 
bag,  and  squeeze  it  with  your  hands.  In  this  way, 
the  gastric  juice  is  well  mixed  with  it.  You  do 
not  know  by  your  feelings  that  your  stomach  is 
contracting  in  this  way.  The  muscle  in  it  is  in- 
voluntary muscle,  and  it  contracts  of  itself. 

When  the  food  has  been  kneaded  in  this  way 
long  enough,  it  slips  out  of  the  stomach  into  the 
bowels. 


DIGESTION.  85 


24.  At  the  beginning  of  the  bowels,  at  the  right 
end  of  the   stomach,  there   is   a   ring   of  muscle 
around   the   tube,    which   is    called   the   pylorus. 
Pylorus  means  "  keeper  of  the  gate."    Until  the 
food  has  been  thoroughly  acted  on  by  the  stomach? 
this  keeper  shuts  the  gate,  and  will  not  let  it  out.    . 

25.  When  you  eat  too  much,  or  take  unwhole- 
some food,  such  as  unripe  fruit,  the  stomach  tries 
to  digest  it,  and  finds  it  can  not.     Then  it  wants 
to  get  rid  of  it.     The  pylorus  will  not  let  the  food 
out  in  that  way;  so  the  stomach  makes  a  great 
effort,  with  the  help  of  some  other  muscles,  and 
throws  it  out  by  the  same  way  through  which  it 
came  in.     Then  the  stomach  feels  better. 

26.  In  1822  a  Canadian,  named  St.  Martin,  was 
shot  in  the  left  side  in  such  a  way,  that,  when 
he  got  well,  there  was  a  hole  into  his  stomach. 
Through  this  hole,  the  inside  of  the  stomach  could 
be  seen,  and  things  could  be  put  in,  and  taken  out. 
In  this  way,  much  of  what  we  know  about  the 
action  of  the  stomach  was  learned. 

27.  When   the   stomach   is   through   with'  the 
food,  the  pylorus  opens  the  gateway,  and  lets  it 
into  the  bowels.     Near  the  beginning  of  the  bowels, 
a  small  opening  can  be  found.    Two  tubes  are  con- 
nected with  this  opening.     One  comes  from  the 
liver,  the  other  from  the  pancreas. 


86 


PHYSIOLOGY    PEIMEE. 


28.  The  liver  is  a  solid  mass  weighing  four 
pounds.  It  is  under  the  edge  of  the  ribs,  most  of 
it  on  the  right  side.  It  makes  yellow  bile  from  the 
blood  which  runs  through  it.  This  bile  is  poured 


Gullet.    Pancreas. 


Gall  Bladde 


Bowels 


Spleen. 


Fig.  19. 

The  Liver  and  other  Organs  of  Digestion. 

out,  through  the  tube  just  spoken  of,  into  the 
upper  end  of  the  bowels.  There  it  mixes  with 
the  food,  and  helps  digestion.  The  liver  also 
makes,  and  stores  up  in  itself,  a  substance  called 


DIGESTION.  87 


glycogen.     Glycogen  is  changed  into  sugar  for  the 
use  of  the  body  as  it  is  wanted. 

29.  The  gall-bladder  is  a  little  sac  shaped  like  a 
pear,  which  is  attached  to  the  under  side  of  the 
liver.      Some   of   the   bile   made   by  the  liver  is 

tored  up  in  the  gall-bladder  when  it  is  not  needed 
in  the  bowels. 

30.  The  tube   from   the   liver   sometimes    gets 
clogged.      That  dams  up  the  bile ;    and  the  bile 
gets  into  the  blood,  and  is  carried  all  through  the 
body.     It  gives  a  yellow  color  to  the  skin  and 
the  eyes.     This  disease  is  called  jaundice. 

31.  The  tube  from  the  pancreas  ends  at  the  same 
opening  with  the  tube  from  the  liver.     The  pan- 
creas is  the  sweetbread  in  calves.     It  is  six  or  seven 
inches  long,  and  lies  across  the  backbone  behind 
the  stomach.     The  fluid  that  it  makes  is  called  the 
pancreatic  juice.     This  mixes  with  the  food  in  the 
bowels,  and  helps  to  digest  it. 

32.  The  lining  of  the  bowels  is  filled  with  little 
pits  similar  to  those  in  the  stomach.     They  make 
the  intestinal  juice. 

Divisions  of  the  Alimentary  Canal. 

The  mouth.  The  oesophagus. 

The  throat.  The  stomach. 

The  bowels. 


88  PHYSIOLOGY    PRIMER. 

Fluids  of  the  Alimentary  Canal. 

The  saliva.  The  bile. 

The  gastric  juice.  The  pancreatic  juice. 

The  intestinal  juice. 

ABSORPTION. 

SECT.  II.  —  1.  Perhaps  you  are  ready  to  ask 
how  the  nutriment  gets  into  the  blood  after  it  is 
prepared  by  digestion,  since  there  is  no  opening 
out  of  the  alimentary  canal. 

If  you  should  examine  the  lining  of  the  ali- 
mentary canal  very  carefully,  you  would  see  that  it 
is  full  of  the  little  blood-vessels  called  capillaries. 
The  walls  of  these  vessels  are  thinner  than  the 
thinnest  paper.  The  nutriment  which  has  been 
dissolved  by  the  juices  in  the  alimentary  canal 
soaks  through  into  these  vessels,  and  is  carried  by 
the  current  of  the  blood  to  all  parts  of  the  body. 
The  soaking  process  is  called  absorption. 

2.  Absorption  goes  on  in  all  parts  of  the 
alimentary  canal.  As  the  nutriment  is  digested, 
it  is  absorbed.  A  good  deal  is  taken  out  of  the 
stomach.  While  the  food  moves  down  through 
the  bowels,  more  and  more  of  it  is  absorbed, 
until  at  last  there  is  no  nutriment  left.  Only 
those  parts  of  the  food  remain  which  can  not 
be  digested. 


RULES  FOR   THE  CARE  OF  THE  STOMACH.  89 

3.  If  we  are  well,  and  eat  only  wholesome  food, 
we  shall  not  have  to  think  any  thing  about  our 
digestion.  It  takes  care  of  itself.  But,  if  we  are 
not  reasonable  about  our  eating,  we  may  have  a 
great  deal  of  trouble.  Dyspepsia  means  bad  diges- 
tion. Since  it  is  our  food  that  gives  us  strength 
and  comfort,  we  shall  not  be  strong  or  happy  if 
we  can  not  digest  well.  Dyspeptics  suffer  a  great 
deal,  and  we  should  take  good  care  not  to  get 
dyspepsia. 

RULES  FOR  THE  CARE  OF  THE  STOMACH. 

SECT.  III.  —  1.  We  should  not  eat  too  fast.  It 
takes  time  to  chew  our  food  properly.  If  we  swal- 
low it  down  in  lumps,  the  stomach  will  have  hard 
labor  to  take  care  of  it. 

2.  We  should  not  eat  too  much.    If  we  feel  heavy 
and  full  after  a  meal,  it  is  a  sign  that  we  are  not 
well,  or  that  we  have  overloaded  our  stomachs. 
It  is  foolish  to  stuff  down  food  which  we  do  not 
need  because  it  tastes  well. 

3.  We  should  not  eat  too  often.     The  stomacli 
needs  rest  as  well  as  the  other  parts  of  the  body. 
If  we  keep  it  at  work  continually,  it  will  wear  out. 

4.  Pie  and  cake  and  candy  should  not  be  eaten 
freely,  like  bread  or  fruit.     A  little  of  such  food  is 
sufficient. 


90  PHYSIOLOGY    PRIMER. 

5.  When  you  find  that  any  thing  you  eat  hurts 
you,  do  not  eat  of  it  again.  If  you  have  eaten 
green  apples  or  cucumbers,  and  have  had  a  stom- 
ach-ache after  it,  let  them  alone  in  future.  If  you 
have  eaten  two  pieces  of  pie,  and  feel  sick,  eat 
only  one  piece  next  time.  If  you  feel  badly  after 
eating  any  thing,  it  is  a  sign  that  it  is  not  good  for 
you.  That  is  the  way  Mother  Nature  teaches  us. 

EFFECTS   OF    ALCOHOL   AND   TOBACCO. 

J$ECT.  IV.  —  1.  Alcohol  is  a  fiery  stimulant.  You 
remember  what  a  stimulant  does  in  your  mouth, 
— such  an  one  as  pepper,  for  instance.  Alcohol 
you  could  not  keep  in  your  mouth  a  moment. 

2.  The  mouth  and  stomach  are  made  for  simple 
food.     If  we  are  well,  they  do  not  need  any  strong 
stimulants.     Too  much  mustard  or  tea  is  bad  for 
them. 

3.  Alcohol  is  a  much  more  dangerous  stimulant 
than  these.     Nobody  drinks   clear  alcohol.     The 
strongest  drinks  are  about  one-half  alcohol,  and 
the  weakest  have  only  three  or  four  spoonfuls  to  a 
tumblerful. 

4.  But  you  have  learned,  that,  when  we   like 
any  stimulant,  we  are  apt  to  want  more  and  more 
of  it,  until  we  get  so  that  we  need  a  great  deal  to 
satisfy  us. 


EFFECT    OF   ALCOHOL    AND    TOBACCO.  91 

No  stimulant  is  so  enticing  as  alcohol.  It  is  very 
easy  to  get  into  the  habit  of  using  a  great  deal  of  it. 

5.  Since  the   stomach  was  not   made   to  need 
strong  stimulants,  it  hurts  it  to  use  them. 

Dr.  Beaumont  found,  that  when  St.  Martin  took 
wine,  beer,  or  any  of  the  intoxicating  liquors 
freely  for  some  days,  the  lining  of  his  stomach 
looked  red  and  inflamed  and  sore,  and  the  gastric 
juice  became  thick  and  ropy. 

6.  If  a  boy  handles  a  bat  a  good  deal,  he  may 
get  his  hands  blistered  at  first.     By  and  by  the 
skin  will  grow  thick  and  hard.     In  the  same  way, 
the  ends  of  a  girl's  fingers  may  get  hardened  by 
sewing.     So,  if  the  stomach  is  irritated  constantly 
by  alcohol,  it  will  grow  thick  and  tough. 

7.  An  old  toper  can  drink  a  great  deal  of  strong 
liquor  without   feeling  it.     That  is   because    his 
stomach  has  changed      It  is  a  better  stomach  to 
hold  alcohol,  but  not  so  good  a  stomach  to  digest 
food. 

8.  Drinking  often   causes    dyspepsia.     It  takes 
away  the  appetite,  and  spoils  the  gastric  juice. 

After  long  use  of  alcohol,  the  stomach  some- 
times gets  into  such  a  condition  that  it  will  not 
bear  food  at  all,  without  being  first  roused  by 
drink. 

9.  Drinking  often  causes  diseases  of  the  liver. 


92  PHYSIOLOGY    PEIMER. 

1C.  He  who  uses  tobacco  for  the  first  time  finds 
to  his  cost  that  it  also  has  a  powerful  effect  on 
the  stomach.  It  has  a  tendency  to  take  away  the 
appetite  for  food,  and,  in  many  cases,  is  one  of 
the  causes  of  dyspepsia. 


QUESTIONS.       ' , 

SECT.  I. — 1,  2.  What  is  the  name  of  the  partition  which  divides 
the  inside  of  the  trunk9  What  is  the  name  of  the  part  above  the 
partition?  of  the  part  below  the  partition? 

3.  What  do  we  notice  in  the  chest  ? 

4.  What  do  we  notice  in  the  abdomen  ? 

5.  If  we  follow  the  gullet  up,  what  do  we  find?    If  we  follow  it 
down,  where  does  it  lead  us?    Where  are  the  bowels  situated? 

6.  What  is  the  name  of  the  long  tube  we  have  just  been  tra- 
cing?   What  is  aliment? 

7.  What  may  the  alimentary  canal  be  compared  to  ?    What  is 
digestion? 

8.  How  long  is  the  alimentary  canal  ?    How  can  so  long  a  tube 
be  contained  in  the  trunk  ? 

9.  Where  does  the  alimentary  canal  begin?    What  is  the  first 
cavity  in  it  ? 

10.  When  do  a  baby's  teeth  begin  to  come?  When  does  he 
have  them  all?  How  many  has  he?  When  does  he  begin  to  lose 
his  first  teeth?  When  does  a  grown  person  have  all  his  teeth? 
How  many  has  he? 

11.  Are  the  teeth  all  alike? 

12.  Describe  a  tooth. 

13.  Do  teeth  decay? 

14.  Why  is  it  important  to  take  care  of  the  teeth?    Mention 
three  rules  for  taking  care  of  the  teeth. 


QUESTIONS.  93 


15.  What  are  the  motions  of  the  lower  jaw  ? 

16.  Describe  the  tongue. 

17.  18.  What  is  done  with  food  in  the  mouth?    What  is  saliva? 
Where  does   it  come  from?    What  is  swollen  when  you   have 
mumps?    How  is  saliva  carried  into  the  mouth?    What  do  you 
mean  when  you  say  your  mouth  waters? 

19.  What  is  the  harm  of  eating  too  fast? 

20.  Describe  the  process  of  swallowing. 

21.  What  is  the  stomach?  its  size?  its  position?    Why  are  we 
short-breathed  when  we  run  after  dinner? 

22.  What  is  the  wall  of  the  stomach  partly  made  of?    What 
are  the  stomach-glands?    What  do  they  make? 

23.  Describe  what  takes    place    in    the    stomach  when    food 
enters  it. 

24.  What  is  the  pylorus?    What  does  it  do? 

25.  How  does  the  stomach  sometimes  relieve  itself  of  indigest- 
ible food? 

26.  How  do  we  know  what  goes  on  in  the  stomach? 

27.  Where  does  the  food  go  when  it  leaves  the  stomach? 

28.  What  is  the  liver?    What  two  things  does  it  do? 

29.  What  is  the  gall-bladder? 

30.  What  is  jaundice? 

31.  What  is  the  pancreas?    What  is  it  for? 

32.  What  is  the  intestinal  juice? 

Name  the  divisions  of  the  alimentary  canal. 
Name  the  fluids  of  the  alimentary  canal. 

SECT.  II.  —  1.  How  does  nutriment  get  into  the  blood? 

2.  Where  does  absorption  go  on  ? 

3.  What  is  dyspepsia? 

SECT.  III.  — 1-5.  Give  five  rules  for  the  care  of  the  stomach, 
with  the  reason  for  each. 

SECT.  IV.  —  1.  What  effect  has  alcohol  in  the  mouth? 


94  PHYSIOLOGY    PRIMER. 

2.  Does  the  healthy  mouth  and  stomach  need  strong  stimu- 
lants? 

3.  Is  clear  alcohol  used  as  a  drink? 

4.  What  is  one  of  the  chief  dangers  of  alcohol  ? 

5.  What  can  alcohol  do  to  the  stomach  ? 

6.  7.  How  may  alcohol  change  the  stomach? 

8.  What  disease  of  the  stomach  does  drinking  often  cause? 

9.  How  does  drinking  affect  the  liver? 

10.  What  effect  may  tobacco  have  on  the  stomach? 


RESPIRATION. 


CHAPTER    VIII. 


RESPIRATION. —THE    VOICE. 

SECT.  I.  —  1.  You  might  live  several  days  with- 
out food  and  water,  but  you  could  not  live  five 
minutes  without  air.  If  any  thing  covers  your 
mouth  or  nose,  so  as  to  prevent  your  breathing, 
you  are  in  distress  until  you  get  it  away.  If  you 
should  sink  under  water,  you  would  die,  because 
the  water  would  shut  out  the  air. 

2.  All  animals  need  air.  Even 
fishes  must  have  it.  There  is  some 
air  dissolved  in  water.  If  you  put  a 
fish  in  a  glass  jar  full  of  water,  and 
then,  with  an  air-pump,  draw  the  air 
out  of  the  water,  in  a  little  while  the 
fish  will  die.  A  fish  breathes  with  his 
gills,  and  they  are  made  to  use  the  air  which  is 
in  the  water.  When  you  take  him  out  of  the 
water,  his  gills  get  dry,  and  do  not  work  well. 
He  dies  for  want  of  air,  as  we  should  in  the 
water. 

Plants,  too,  would  soon  perish,  if  you  could 
take  the  air  entirely  from  them. 


Fig.  2O. 

The  Gills  of  an 
Eel. 


96  PHYSIOLOGY    PRIMER. 

Because  air  is  necessary  for  us  all  the  time,  the 
Creator  has  given  it  to  us  freely.  We  have  to 
work  for  our  food.  Even  water  may  be  scarce. 
But  every  one  can  have  as  much  air  as  he  needs, 
without  price.  We  have  only  to  breathe  it. 

3.  What  is  breathing  f     Drawing  the  air  in,  and 
letting  it  go  out,  you  say.     But,  if  I  ask  you  how 
you  draw  it  in,  you  might  not  be  able  to  tell  me, 
though  it  is  perfectly  easy  for  you  to  do  it. 

4.  When  we  looked  into  the  chest,  we   found 
there,  besides  the  heart  and  the  gullet,  two  lungs, 
one    on    each  side.     They    are    smooth,    pinkish 
masses,  and  not  so  hard  but  that  you  can  poke 
your  finger  through  one.     You  can  easily  get  some 
to  examine  at  the  butcher's.     He  calls  them  the 
"lights." 

5.  The  root  of  each  lung  is  a  bundle  of  tubes, 
which   lie   close   together.      These  tubes  are  the 
blood-vessels  which  go  to  and  from  the  heart,  and 
the  air-tube.     The  air-tubes  of  the  two  lungs  join, 
in  front  of  the  backbone,  to  form  the  trachea,  or 
windpipe.     The   windpipe   is   four  or  five   inches 
long,  and  from  half  an  inch  to  an  inch  across. 
If  you  follow  it  up  through  the  neck,  you  find 
that  it  opens  into  the  throat,  and  so  connects  with 
the  mouth  and  nose. 

It  is  through  the  mouth  and  nose  that  the  air  is 
drawn  in. 


RESPIRATION. 


97 


Larynx. 


Fig.   21. 

Heart  and  Lungs. 

6.  The  nose  is  the  true  breathing-passage.     The 
two  openings  of  the  nose  we  call  the  nostrils.     Be- 
yond  these   openings   are   two   high  and  narrow 
passage-ways,  which  go  straight   back,  and   open 
into  the  throat  just  above  the  palate. 

7.  There  are  two   reasons  why  it  is  better  to 
breathe  through  the  nose  than  through  the  mouth. 

The  first  reason  is,  that  the  air  gets  warmed  in 
passing  through  the  nose.     The  passages  are  nar- 


98  PHYSIOLOGY    PRIMER. 


row;  and  the  stream  of  air  is  therefore  thinner, 
and  more  easily  warmed  by  the  warm  walls. 

The  second  reason  is,  that  the  air  gets  moistened 
in  passing  through  the  nose.  The  walls  of  these 
narrow  passages  are  lined  with  a  reddish  mem- 
brane, like  the  lining  of  the  mouth.  It  is  both 
warm  and  moist,  and  gives  its  moisture  to  the  thin 
stream  of  air. 

8.  When  we  breathe  through  the  mouth,  the  air 
is  colder  and  drier  when  it  reaches  the  throat.    We 
all  know  how  dry  the  mouth  will  get  when  we  run, 
and  breathe  fast  through  it.     People  who  breathe 
through  the  mouth  all  the  time  are  more  liable  to 
have  sore  throats. 

9.  Whoever  has  a  disease  which  stops  up  the 
nose,  and  prevents  his  breathing  through  it,  ought 
to  have  it  cured  if  possible. 

Snoring  is  caused  by  breathing  through  the 
mouth.  People  who  sleep  with  their  mouths 
closed  do  not  snore. 

1C.  Besides  serving  us  for  breathing,  the  nose 
is  the  organ  of  smell.  The  nerves  of  smell  are  in' 
the  upper  part  of  the  nose.  Therefore,  if  we  wish 
to  smell  any  thing  distinctly,  instead  of  drawing 
the  air  quietly  through  in  the  usual  way,  we  sniff, 
and  draw  it  up. 

11.  The  food  and  the  air  both  go  into  the  throat. 


RESPIRATION. 


99 


There  they  part  company.  The  food  goes  down 
the  gullet,  and  the  air  goes  down  the  windpipe. 
Sometimes  we  swallow  a  little  air.  Sometimes  a 
drop  of  water,  or  a  particle  of  food,  is  "  swallowed 
the  wrong  way,"  and  gets  into  the  windpipe.  This 
makes  us  cough  furiously  until  we  get  it  out.  But 
generally  food  and  air  each  takes  its  own  course. 
It  is  wonderful  that  they  do  so.  There  are  nerves 
that  keep  guard  over  the  entrance  to  the  windpipe, 
and  make  it  open  and  close  at  the  right  time,  as 
the  switch-tender  at  the  depot 
opens  and  closes  the  switches, 
and  sends  each  train  on  its  own 
track. 

12.  The  upper  end  of  the 
windpipe  is  a  kind  of  a  box. 
You  see  it  in  the  figure  (Fig. 
22),  and  you  can  feel  it  in  your 
own  neck.  It  is  called  "  Adam's 
apple."  Its  sides  are  made  of 
cartilage,  which  is  almost  as  stiff 
as  bone,  but  not  so  heavy.  This 
box  is  the  larynx,  or  voice-box. 

13.  The  vocal  cords  are  two 
elastic  cords  or  bands,  which  stretch  across  the 
larynx.  They  can  be  tightened  or  loosened ;  and 
they  can  be  spread  wide  apart,  or  brought  together 


Fig.  22. 

THE  LARYNX.  -  1.  Adam' 
Apple.  -2.  Trachea. 


100  PHYSIOLOGY    PRIMtfR. 

so  as  to  close  the  passage-way  entirely.  When  we 
wish  to  make  a  sound,  we  make  our  breath  go  out 
quickly.  As  it  passes  between  these  cords,  it  sets 
them  in  motion,  and  makes  a  sound  in  the  same 
way  that  sound  is  made  in  the  pipe  of  an  organ 
by  the  wind  which  the  organ-blower  pumps 
through  it.  If  the  cords  are  tight,  and  near  to- 
gether, the  tone  will  be  high.  If  they  are  loose, 
and  wide  apart,  the  tone  will  be  low. 

14.  The  larynx  differs  a  little  in  shape  and  size 
in   different   people.     The   vocal   cords    differ  in 
length  and  thickness.     So  voices  vary,  like  the 
tones  of  musical  instruments. 

15.  The  muscles  of  the  larynx  grow  strong  by 
exercise,  as  other  muscles  do.     By  training  our 
voices  in  singing  and  speaking,  they  may  be  made 
stronger  and  better. 

16.  If  we  wish  to  improve  our  voices,  and  learn 
to  use  them  well,  we  must  take  pains.     Those  who 
are  careless,  and  make  no  effort  to  speak  distinctly 
and  correctly,  never  can  do  so. 

17.  The  windpipe  has  fifteen  or  twenty  rings  of 
cartilage  in  its  wall.     They  are  stiff,  and  keep  the 
tube  wide  open  all  the  time.     It  is  directly  in  front 
of  the  gullet. 

It  divides  into  two  tubes,  which  are  just  like 
itself,  which  go  to  the  two  lungs.     Each  one  when 


RESPIRATION. 


101 


it  reaches  the  lungs  divides ;  and  the  branches 
divide  again,  and  keep  on  dividing,  until  they  be- 
come almost  as  small  as  hairs ;  and  then  they  end 


Bronchial 
tubes. 
A 


Larynx. 


Fig.  23. 

Section  of  the  Lungs,  partly  showing  the  Course  of  the  Bronchial  Tubes. 

in  little  bunches  of  air-cells.     These  tubes  in  the 
lungs  are  called  bronchial  tubes. 

18.  The  air-tubes  may  be  compared  to  a  tree. 
The  large  tube  which  goes  to  the  lung  is  the  trunk. 
Just  as  the  trunk  divides  into  limbs,  branches,  and 
twigs,  so  the  air-tube  divides  in  the  lung.  The 


102 


PHYSIOLOGY    PRIMER. 


air-cells  are  like  the  leaves  in  which  the  branches 
end  at  last. 

19.  But  the  lung  is  not  all  air-tubes  and  air- 
cells.     It  also  contains  blood-vessels.    The  branches 

of  the  pulmonary  artery  enter 
it  by  the  side  of  the  air-tube, 
and  they  divide  just  as  the  air- 
tube  divides ;  and  finally  the 
little  capillaries  lie  on  the  out- 
side of  the  air-cells,  forming  a 
network  over  them.     If  you 
imagine   the  air-tubes    to    be 
like  a  tree,  you  can  imagine 
the   blood-vessels   to   be   like 
a  vine  climbing  the  tree,  and 
following    all    its    limbs    and 
branches  out  to  the  smallest  twigs  and  the  leaves. 
There  are  some  other  things  in  the  lungs ;  but 
these  two  —  the  air-tubes  and  the  blood-vessels — 
are  all  you  need  to  think  of  at  present. 

20.  The  air  tubes  and  cells  in  the  lungs  always 
contain  air.     By  breathing,  we  change  the  air  in 
them,  and  keep  it  fresh. 

What  good  does  that  do  us  ?  Why  do  we  want 
fresh  air  in  them? 

Because  we  want  oxygen.  Air  is  partly  made 
of  a  gas  called  oxygen.  Nothing  can  live  without 


Fig  24. 


Bronchial  Tubes  and  Air -Cells. 


RESPIRATION. 


103 


oxygen.  Every  bit  of  our  bodies  is  calling  for 
oxygen  all  the  time.  So  the  blood  hurries  up  to 
the  lungs,  and  gets  it,  and  then  hurries  away  to 
distribute  it,  and  then  back  again  for  another 
supply,  and  so  on  constantly.  The  air  itself  does 
not  get  into  the  blood,  but  the  oxygen  that  is 
in  the  air  does.  The  little  capillaries  lie  on  the 
air-cells,  and  the  walls  of  both  capillaries  and  air- 
cells  are  thin  as  a  soap- 
bubble.  The  oxygen  passes 
through  these  walls  into  the 
blood,  as  the  nourishment 
passes  from  the  alimentary 
'canal  into  the  blood. 

21.  But  we  have  not  yet 
answered  the  question, 
How  do  we  draw  the  air 
into  the  lungs?  If  you 
take  hold  of  the  handles 
of  a  pair  of  bellows  or  of 
an  accordion,  and  pull 
them  apart,  the  air  will 
rush  in.  If  you  let  go  the  handles,  they  will  grad* 
ually  come  together,  and  the  air  will  pour  out. 
That  is  the  way  the  air  is  made  to  go  into  and  out 
of  the  lungs.  You  remember  that  the  diaphragm 
is  a  muscle,  and  can  move  up  and  down.  When 


104  PHYSIOLOGY  PRIMER. 

we  take  a  breath,  it  moves  down,  and  the  sides  and 
front  of  the  chest  swell  out.  The  diaphragm  and 
the  walls  of  the  chest  pull  the  elastic  lungs  with 
them,  and  stretch  them  open.  Then  the  air  must 
rush  in  through  the  air-tubes,  and  fill  them. 

Down  and  up  the  diaphragm  keeps  moving, 
and  the  breast  keeps  rising  and  falling,  and  the 
breaths  of  air  go  in  and  out  as  the  waves  corns 
and  go  on  the  beach. 

22.  The  breath  which  comes  out  is  not  so  pure 
as  the  breath  which  goes  in.     It  has  lost  part  of 
its  oxygen ;  and  it  has  received  from  the  blood  in 
exchange  a  gas,  which  we  call  carbonic-acid  gas. 

If  many  people  are  in  a  room,  they  will  soon 
make  all  the  air  in  it  impure  by  their  breathing. 
If  no  fresh  air  is  let  in,  there  will  not  be  enough 
oxygen  after  a  time  to  keep  them  alive. 

23.  We  do  not  feel  comfortable  when  we  are 
breathing  impure   air.      The   room    seems    close, 
and  we  feel  stifled.     We  may  be  sleepy  and  dull. 
People  often  suffer  from  these  bad  feelings  with- 
out knowing  what  is  the  cause  of  them.     If  they 
would  go  out  of  doors,  or  open  their  windows,  and 
let  in  the  air,  they  would  feel  better. 

24:.  Any  bad  smell  in  the  air  shows  that  there 
is  something  in  it  which  ought  not  to  be  there. 
It  is  a  sign  of  danger. 


EFFECT   OF  ALCOHOL   AND   TOBACCO.  105 

25.  The  blood  in  the  veins  has  a  dark  purple 
tinge.     From  the  right  ventricle  of  the  heart  this 
dark  blood  goes   through   the  pulmonary  artery 
to   the  lungs.      When   it  comes   from  the  lungs 
through  the  pulmonary  veins,  it  is  bright  scarlet 
What  has  caused  this  change?     It  is  the  oxygen 
that  is  taken  from  the  air.     Besides  gaining  oxy- 
gen, the  blood,  while  passing  through  the  lungs, 
has  lost  carbonic-acid  gas. 

26.  From  the  left  side  of  the  heart  the  scarlet 
blood  is  sent  all  through  the  body.     When  it  gets 
into  the  capillaries,  it  grows  dark  again.     That  is 
because  it  is  giving  up  its  load  of  oxygen.     At  the 
same  time,  it  takes  in  from  the  particles  around 
the  capillaries,  a  load  of  carbonic-acid  gas.     The 
oxygen  is  like  the  fuel  that  keeps  the  fire  of  life 
going,  and  the  carbonic-acid  gas  is  like  the  ashes. 
So  the  blood  gives  fuel,  and  takes  up  ashes,  and 
carries  them  to  the  lungs,  where  they  are  thrown 
out  in  the  breath.     It  is  not  good  to  breathe  in  a 
room  full  of  ashes  and  smoke.     Neither  is  it  good 
to  breathe  in  a  room  full  of  carbonic-acid  gas  from 
the  breaths  of  many  people. 

EFFECT   OF   ALCOHOL   AND   TOBACCO. 

SECT.  II.  —  1.  Some  people  think  that  alcoholic 
drinks  prevent  consumption     Those  who  try  to 


106  PHYSIOLOGY    PRIMER, 

escape  it  in  this  way  may  fall  into  evils  that  are 
much  worse. 

2.  When  more  than  a  small  amount  of  alcohol 
is  taken,  it  goes  out  of  the  body  partly  in   the 
breath.      Habitual  drinkers  are  known  by  their 
breaths. 

3.  Tobacco  also  clings  to  the  breath,  and  gives 
it  a  stale  and  unpleasant  odor.      It  defiles   and 
blackens  the  teeth. 

4.  When  tobacco-smoke  is  drawn  down  into  the 
lungs,  it  has  a  more  powerful  effect  than  when  it 
is  puffed  directly  out  of  the  mouth.     The  nico- 
tine which  it  contains  passes  in  greater  quantities 
through  the  delicate  walls  of  the  air-cells  into  the 
blood. 


QUESTIONS. 

SECT.  I.  —  1.  What  three  things  are  necessary  to  maintain  life? 
Which-  can  we  spare  the  longest  ? 

2.  Can  animals  live  without  air?    Can  plants?    What  is  the 
most  abundant  gift  of  God  to  us  ? 

3.  What  is  breathing? 

4.  What  is  in  the  chest? 

5.  What  are  the  roots  of  the  lungs  made  of?    What  is  the 
trachea?    How  long  is  it?    How  wide?    What  does  it  open  into? 

6.  What  is  the  true  breathing-passage  ?    What  are  the  nostrils  ? 
What  does  the  nose  open  into  behind? 

7.  What  is  the  first  reason  named  for  breathing  through  the 
nose  rather  than  the  mouth?    What  is  the  second? 

8.  What  is  the  effect  of  breathing  through  the  mouth? 


QUESTIONS.  107 


9.  What  is  the  cause  of  snoring? 

10.  Why  do  we  snuff  when  we  wish  to  smell  keenly? 

11.  Why  does  not  food  go  into  the  windpipe? 

12.  What  is  the  larynx?    What  is  Adam's  apple? 

13.  What  are  the  vocal  cords?    How  is  sound  made? 

14.  What  makes  the  difference  in  voices? 

15.  Why  does  the  voice  grow  strong  by  exercise? 

16.  Can  we  talk  or  sing  well  without  effort? 

17.  How  is  the  windpipe  made?     What  are  the  bronchial 
tubes? 

18.  What  may  the  air- tubes  be  compared  to? 

19.  What  does  the  lung  contain  besides  air-tubes?    What  may 
the  blood-vessels  be  compared  to? 

20.  What  do  the  air  tubes  and  cells  contain?    Why  do  we  want 
to  keep  the  air  in  them  fresh?     What  is  oxygen?     Does  air  get 
into  the  blood?    How  does  oxygen  get  into  the  blood? 

21.  How  do  we  draw  the  air  into  the  lungs? 

22.  How  is  our  breath  changed  when  it  comes  out?    How  is 
the  air  of  a  room  in  which  are  many  people  changed? 

23.  What  is  the  effect  of  impure  air  on  us? 

24.  What  does  a  bad  smell  indicate? 

25.  What  is  the  color  of  blood  in  the  veins?  in  the  arteries? 
Where  does  it  change  from  purple  to  scarlet?    What  causes  the 
change? 

26.  Where  does  it  change  from  scarlet  to  purple?    What  causes 
the  change?    What  may  oxygen  in  the  body  be  compared  to? 
What  may  carbonic-acid  gas  be  compared  to? 

SECT.  II.  —  1.  Which  is  worse,  consumption  or  drunkenness? 

2.  What  effect  has  alcohol  on  the  breath  ? 

3.  What  effect  has  tobacco  on  the  breath?  on  the  teeth? 

4.  Why  is  tobacco-smoke  more  injurious  when  it  is  breathed 
into  the  lungs? 


IVERSITY 


108  PHYSIOLOGY    PRIMER. 


CHAPTER    IX. 


THE    NERVOUS    SYSTEM.— THE    EYE.  ~- 
THE    EAR 

SECT.  I.  —  1.  When  people  are  tired  or  ill,  they 
sometimes  feel  nervous.  That  means  that  their 
nerves  are  not  in  good  order.  Noises  trouble 
them.  They  are  liable  to  make  mistakes,  and  can 
not  thread  a  needle,  or  catch  a  ball,  or  do  other 
easy  things,  as  well  as  usual. 

Perhaps  you  have  sometime  seen  in  the  street  a 
large,  strong  man,  who  could  not  walk  any  better 
than  a  baby.  He  reeled  and  staggered,  and  finally 
fell  as  helpless  as  a  sack  of  meal.  If  you  asked 
what  was  the  matter  with  him,  you  were  told 
that  he  had  been  drinking,  and  that  the  drink  had 
affected  his  brain.  His  muscles  were  as  strong  as 
ever,  but  they  would  not  hold  him  up  because 
his  brain  was  out  of  order. 

It  is  evident  that  the  nerves  and  the  brain  have 
a  good  deal  to  do  with  the  action  of  our  muscles. 

It  is  time  to  inquire  what  the  nerves  and  the 
brain  are,  and  how  they  act.  We  shall  find  that 
are  the  most  important  part  of  the  body. 


THE    NERVOUS    SYSTEM. 


109 


Cerebrum. 

IUjpr. Cerebellum. 


Spinal  cord. 


Fig.  26. 

General  Representation  of  the  Nervous  System. 


110  PHYSIOLOGY    PEIMEE. 

2.  You  know  that  the  brain  is  in  the  skull. 
If  you  cut  through  the  skull  of  a  dead  animal, 
you  can  take  the  brain  out.     It  is  soft,  part  white, 
and  part  gray.     The  brain  of  an  intelligent  ani- 
mal, like  a  cat  or  dog,  is  very  much  like  the  brain 
of  a  man. 

But,  with  two  exceptions, — the  whale  and  the 
elephant, — no  animal  has  as  large  a  brain  as  man. 

3.  We  know  that  it  is  in  the  brain  that  thinking 
is  done,  and  willing,  and  remembering.     For,  if  a 
man's  brain  is  hurt  or  diseased,  he  partly  loses  the 
power  of  thinking  and  willing  and  remembering. 
If  his  muscles  or  his  heart  or  his  stomach  are 
diseased,  it  may  not  affect  his  mind  at  all.     Be- 
sides, experiments  have  been  made  on  animals  to 
find  out  what  the  brain  does.     These  experiments 
show,  that,  when  the  brain  is  taken  out,  the  animal 
does  not  know  any  thing.      He  may  have   the 
power  of  moving,  but  what  mind  he  had  is  gone. 

Since  man  can  think  and  remember  and  know 
so  much  more  than  the  lower  animals,  we  should 
expect  that  his  brain  would  be  larger,  as  it  is. 

4.  From  the  under  part  of  the  brain,  a  cord 
about  as  large  as  your  little  finger  extends  down 
like  a  Chinaman's  cue.     This  cord  lies  in  the  cen- 
ter of  the  backbone,  and  is  called  the  spinal  cord. 
It  is  soft  and  cheesy,  like  the  brain,  and  is  part 


THE    NERVOUS    SYSTEM.  Ill 

white,  and  part  gray,  in  color.     The  brain  and  the 
spinal  cord  are  called  the  nerve-centers. 

5.  The  brain  and  the  spinal  cord  are  both  made 
in  halves,  which  are  exactly  alike,  and  are  joined 
in  the  middle. 

6.  From  each  half  of  the  brain,  twelve  small 


Fig.  27. 

Half  of  the  Brain,  and  upper  end  of  the  Spinal  Cord,  with  the 
Nerves  coming  from  them. 

cords  branch  off;  and  from  each  half  of  the  spinal 
cord,  thirty-one  small  cords  branch  off. 

These  cords  are  the  nerves.  Those  which  come 
from  the  brain  pass  through  holes  in  the  skull 
to  different  parts  of  the  head  and  neck  and  chest. 
The  olfactory  nerves  lead  to  the  nose,  and  are 


112  PHYSIOLOGY    PRIMER. 

the  nerves  of  smell.  The  optic  nerves  lead  to  the 
eyes,  and  are  the  nerves  of  sight.  The  auditory 
nerves  lead  to  the  ears,  and  are  the  nerves  of  hear- 
ing. Others  lead  to  the  tongue  and  the  skin  and 
other  parts. 

7.  The  nerves  from  the  spinal  cord  come  out 
of  the  spinal  canal  in  the  backbone,  and  lead  to 
all  parts  of  the  body  below  the  head. 

8.  A  nerve  is  a  white  and  shining  cord.     The 
sciatic  nerve,  which  is  the  largest  in  the  body, 
is  as  much  as  half  an  inch  wide.     The  smallest 
nerves  can  not  be  seen  without  a  microscope. 

9.  If  you  should  follow  one  of  them  from  the 
backbone,  you  would  find  it  giving  off  branches, 
and  joining  with  other  nerves,  but  growing  smaller 
the  farther  you  go.     At  the  end  it  divides  up  into 
fibers,  which  reach  every  bit  of  the  part  it  sup- 
plies.     For   example,  suppose  you   start  on  one 
of  the  nerves  from  the  neck-part  of  the  spinal 
cord.     Directly   you   find   it  joining  with   other 
nerves,  and  making  quite  a  network.     This  net- 
work   extends    down    into    the    armpit.      There 
several   branches  start  off,  which  go  to  different 
parts   of  the   arm   and    hand.      Follow   the   one 
which  is  called  the  ulnar  nerve.     That  runs  down 
the  inner  side  of  the  arm.     When  it  gets  to  the 
elbow,  it  passes  just  under  a  point  of  bone  known 


THE    NERVOUS    SYSTEM.  113 

as  the  "  funny  bone."  If  you  happen  to  hit  this 
point  of  bone,  you  are  very 
likely  to  bruise  the  ulnar 
nerve,  and  then  you  have  a 
tingling  sensation  down  to 
the  end  of  your  little  finger. 
The  ulnar  nerve  below  the 
elbow  lies  just  in  the  line  of 
this  sensation,  and  it  ends  in 
the  little  finger.  If  you  fol- 
lowed it  into  the  skin,  you 
would  have  to  use  a  micro- 
scope; and  in  that  way  you 
would  see  the  network  that 
it  makes.  The  network  is 
so  close,  that  you  could  not 
prick  your  finger  with  a  fine 
needle  without  hurting  one 
of  the  little  fibers  of  it. 

Nearly  every   part   of  the 
body    is    full    of   these    fine  Flg-  28- 

NERVES    OF    THE     FORE- ABM 

nerve-endings.  AND  HAND.  - 1.  Artery.  2. 

1C.  Now,    if   you    under- 
stand how  the  nerves  are  in  all  parts  of  the  body, 
and  how  they  are  all  connected  with  the  spinal 
cord  or  brain,  we  are  ready  to  inquire  what  the 
nervous  system  does. 


114  PHYSIOLOGY    PRIMER. 

ACTION    OF    THE    NERVOUS    SYSTEM. 

11.  If  you  live  in  the  city,  you  have  often 
looked  at  the  wires  of  the  telegraphs  and  tele- 
phones over  the  tops  of  the  houses,  —  hundreds  of 
them  running  in  every  direction.  And  you  know 
what  they  are  for.  They  connect  the  different 
parts  of  the  city;  so  that,  if  a  man  in  his  home 
wants  to  speak  to  the  clerks  in  his  store,  he  can  do 
it,  though  he  is  a  mile  away.  If  a  lady  wishes  to 
order  meat  for  dinner,  she  .can  call  the  butcher 
without  stepping  outside  her  own  door.  If  there 
is  danger  from  burglars,  a  message  goes  along  the 
wire,  and  brings  a  policeman.  If  there  is  a  fire,  it 
calls  the  engines.  And  so  the  people  in  the  city 
can  talk  together  about  many  things,  and  help 
each  other. 

±2.  The  nervous  system  is  in  the  body  what 
the  telegraph  system  is  in  the  city.  The  nerves 
are  like  the  wires,  and  the  brain  and  spinal  cord 
are  like  the  offices. 

The  different  parts  of  the  body  must  work  to- 
gether, and  help  each  other.  Suppose  the  stomach 
wants  food.  How  can  it  get  it  unless  the  hands 
pick  it  up,  and  the  throat  swallows  it?  When 
the  stomach  wants  food,  we  feel  hungry.  That 
is  the  message  that  goes  through  the  nerves  to  the 


ACTION    OF    THE    NERVOUS    SYSTEM.  115 

brain,  "  I  am  hungry."  Then  the  brain  sends 
orders  out  to  the  muscles,  and  they  walk  us  to 
the  dinner-table ;  and  then  other  muscles  pick 
up  the  food,  and  others  carry  it  down  the  throat 
to  the  stomach. 

Suppose  some  one  has  thrown  a  ball  at  youf 
head.  You  see  it  coming.  The  message  goes  in 
along  the  optic  nerves  to  the  brain.  The  brain 
sends  out  an  order  to  certain  muscles,  which  raise 
the  hands  to  stop  it. 

13.  Whenever  we  see  or  hear  or  smell  or  taste 
or  touch  any  thing,  a  message  goes  in  over  the 
nerve  of  the  eye  or  the  ear  or  the  nose  or  the 
tongue,  or  the  part  that  is  touched,  to  the  spinal 
cord  or  the  brain,  and  the  spinal  cord  or  the  brain 
sends  out  its  orders  along  other  nerves. 

14.  If  a  man  breaks  his  back,  he  may  not  die 
immediately,  but  he  will  not  be  able  to  move  his 
legs,  and  he  will  not  feel  it  if  you  prick  or  pinch 
them.     He  is  paralyzed  below  the  place  where  his 
back  is  broken.     The  nerves  in  the  legs  connect 
with  the  spinal  cord,  and  the  spinal  cord  connects 
with  the  brain.      When  the  back  is  broken,  the 
wires  are  cut.     There  is  no  connection  between 
the  brain  and  the  legs.     The  brain  may  will  that 
the  legs  should  move,  but  it  can  not  send  the  mes- 
sage down.     The  legs  may  be  pricked  or  pinched, 


116  PHYSIOLOGY    PRIMER. 

but  the  brain  does  not  know  it.     The  message 
can  not  go  up. 

15.  All  our  feelings  of  hunger,  thirst,  heat  or 
cold,  or  pain  or  weariness,  are  carried  to  the  brain 
by  the  nerves.     All  our  movements  are  made  by 
the  action  of  the  nerves.     When  the  nerves  and 
brain  stop  acting,  we  no  longer  feel  or  think  or 
move. 

HEALTH  OF  THE  NERVOUS  SYSTEM. 

16.  Since  the  brain  and  nerves  have  such  im- 
portant work  to  do,  we  should  keep  them  in  good 
condition  if  possible. 

In  order  that  the  brain  may  be  clear,  and  the 
nerves  strong,  we  need, — 

(1.)  Plenty  of  fresh  air.  You  remember  that  we 
want  air  for  the  sake  of  the  oxygen  in  it.  No  part 
of  the  body  has  such  constant  need  of  oxygen  as 
the  nervous  system.  The  brain  has  a  great  deal 
of  blood  sent  to  it;  and,  if  the  blood  is  cut  off 
for  an  instant,  it  will  stop  acting.  If  there  is  too 
little  oxygen  in  the  air,  the  brain  grows  dull,  and 
the  head  feels  uncomfortable. 

(2.)  We  need  plenty  of  exercise.  Exercise  makes 
us  breathe  faster,  and  makes  the  blood  move 
quickly;  and  so  the  nerves  and  brain  get  more 
oxygen.  If  we  have  been  sitting  still  an  hour,  ten 
minutes  of  running  and  jumping  makes  us  feel 


HEALTH    OF    THE 


brighter.  Children  need  exercise  and  air  more 
than  grown  people. 

(5.)  We  need  good  plain  food.  The  nerves  re- 
quire nourishment  as  well  as  oxygen.  If  we  do  not 
have  food  enough,  or  if  we  spoil  our  digestion  by 
eating  too  much  candy  or  rich  food,  the  nervous 
system  will  be  starved  and  weak. 

(4.)  We  need  plenty  of  sleep.  All  day  the  brain 
and  nerves  are  very  active.  They  must  rest  at 
night,  or  they  will  soon  wear  out.  A  healthy  per- 
son may  sit  up  one  night,  or  even  several  if  he  is 
strong  ;  but  it  is  torture  for  any  one  to  be  deprived 
of  sleep  for  many  days.  This  is  because,  while  we 
are  awake,  the  brain  and  nerves  are  wearing  out  a 
little  faster  than  they  are  being  repaired.  In  the 
night  they  are  repairing  faster  than  they  are  wear- 
ing, and  by  morning  they  are  as  good  as  they  were 
the  morning  before. 

A  baby  a  few  days  old  sleeps  almost  all  the  time. 
As  he  grows  older,  he  sleeps  less.  Children  need 
much  more  sleep  than  grown  people.  Their  ner- 
vous systems  are  more  delicate,  and  wear  faster. 
Besides,  they  are  growing,  and  ought  to  be  a  little 
larger  and  stronger  every  morning. 

Sitting  up  late  at  night  makes  pale  faces  and 
weak  limbs  and  irritable  nerves. 

(5.)  We  need  change  of  occupation.     Change  is 


118  PHYSIOLOGY    PRIMER. 

rest.  If  we  have  been  studying,  it  rests  us  to  run. 
If  we  have  been  playing  hard,  it  rests  us  to  sit 
down  with  a  book.  It  is  not  wise  for  a  child  to 
read  too  long  at  one  time.  Out  of  school  he 
should  be  playing,  or  working  in  some  other  way. 

THE    EYE. 

SECT.  II.  —  1.  The  eyes  are  placed  in  two  cavi- 
ties called  the  orbits.  The  eyeball  is  a  sphere 
about  an  inch  in  diameter.  It  does  not  fill  the 
orbit.  There  is  considerable  space  around  it  and 
behind  it,  which  is  padded  with  fatty  tissue.  This 
makes  a  cushion  for  it  to  rest  on.  The  eyelids, 
with  their  long  lashes,  are  to  protect  the  eye.  The 
eyebrows  are  a  kind  of  awning,  which  keeps  off 
the  perspiration  that  might  trickle  down  from  the 
forehead. 

2.  In  the   orbit,  just  over  the  eyeball,  is   the 
lachrymal  gland.     This  is  a  gland  of  about  the 
size  and  shape  of  an  almond.     It  is  filled  with 
blood-vessels,  and  makes  tears  in  the  same  way  in 
which  the  sweat-glands  make  perspiration.     The 
vfater  comes  out  of  it  by  little  tubes,  and  flows  over 

he  surface  of  the  eye.     Ordinarily  there  is  just 
;nough  to  keep  the  eye  moist  and  smooth. 

3.  At  the  inner  end  of  the  edge  of  each  eyelid 
Is  a  hole  as  large  as  the  point  of  a  pin.     You  can 


THE    EYE. 


119 


easily  find  it  on  the  lower  eyelid.  These  holes  are 
the  beginnings  of  little  ca- 
nals that  carry  off  the  water. 
The  canal  from  the  upper, 
and  that  from  the  lower  lid, 
come  together  in  a  sac  in 
the  inner  corner  of  the  or- 
bit, which  is  called  the  lach- 
rymal sac.  From  the  lach- 
rymal sac  a  canal  called  the 
nasal  duct  runs  straight 
down  into  the  nose.  Ordi- 
narily the  Water  Can  easily  LACHRYMAL  APPARATUS. - 

nn      ,1  i         ,  i  1.  Lachrymal  gland.    2.  Tear-pas- 

flOW    Oil      thrOUgh     tn68e     Ca-        sages.    S.  Lachrymal   sac.    4.  Na- 

nals.  We  do  not  notice  it  sal  duct> 
in  the  nose.  But  when  we  feel  badly,  or  when  a 
cold  wind  blows  in  our  faces,  or  when  we  get  dust 
in  our  eyes,  the  lachrymal  glands  are  very  active. 
The  water  runs  into  our  noses  so  rapidly  that  we 
have  to  use  a  pocket-handkerchief;  and,  besides, 
it  runs  over  on  our  cheeks,  making  tears.  The 
first  thing  you  do,  when  you  cry,  is  to  put  your 
knuckles  to  your  eyes  to  rub  the  tears  out. 

4.  We  see  only  the  front  of  the  eyeball  when  it 
is  in  its  place.  In  the  center  is  a  round  black 
hole.  This  is  the  pupil.  The  colored  part,  which 
may  be  black  or  brown  or  blue  or  gray,  is  the  iris. 


120  PHYSIOLOGY    PllIMEE. 

You  notice  that  the  pupil  is  large  when  the  eye  is 
in  the  shade,  and  small  when  it  is  in  a  strong 

light.  That  is  because 
the  iris,  which  is  made 
in  part  of  muscle-fibers, 
changes  its  shape.  It  is 
a  curtain  with  a  hole  in 
it,  and  its  use  is  to  pro- 
aT  tect  the  inside  of  the  eye 

Flg-  30-  from  too  much  light. 

THE    EYE.  — 1.  Pupil.     2.  Iris.     3.  Sclerotic 

coat.  5.  If  you  look  from 

the  side  at  the  front  of  an  eye,  you  will  see,  that, 
before  the  iris,  there  is  a  transparent  cover,  which 
is  like  a  watch-glass  in  shape.  This  is  the  cornea. 
All  around  the  cornea  is  the  white  of  the  eye.  The 
white  is  the  outside  coat  which  covers  the  whole 
of  the  ball  except  the  part  where  the  cornea  is.  It 
is  called  the  sclerotic  coat. 

G.  Get  an  ox-eye  from  the  butcher's,  and  exam- 
ine it.  You  will  see  all  these  things  on  the  front. 
Attached  to  the  sides,  you  may  find,  if  it  has  not 
been  trimmed  off  carefully,  several  slips  of  red 
muscle.  These  are  the  muscles  which  move  the 
ball,  and  roll  it  in  every  direction.  At  the  back 
part,  you  will  find  a  firm  white  stem,  like  the  stem 
of  a  grape.  This  is  the  optic  nerve,  which  has 
been  cut  off  in  taking  the  eye  out.  It  comes  from 


THE    EYE. 


the  brain,  through  a  hole  in  the  back  part  of  the 
orbit,  and  passes  through  the  coats  of  the  ball,  and 
then  spreads  out,  and  makes  a  lining  for  these 
coats.  This  lining  is  called  the  retina. 

7.  Now,  cut  through  the  ball.     It  is  filled  with 
fluid.     The  ball  collapses  as  a  grape  would  if  you 


Fig.  31. 

Eyeball  and  Optic  Nerve. 

should  cut  it  open.  If  you  are  careful,  you  will 
find  in  it  a  hard,  transparent  body  shaped  like  a 
small  button.  This  is  the  lens. 

8.  Now  you  have  seen  the  principal  parts  of  the 
eyeball.     They  are, — 

The  sclerotic  coat.  The  retina. 

The  cornea.  The  fluid  contents. 

The  iris.  The  lens. 

The  parts  outside  the  ball  are,  — 


122  PHYSIOLOGY    PRIMES. 

The  eyebrows.  The  lachrymal  gland. 

The  eyelids.  The  lachrymal  sac. 

The  eyelashes.  The  nasal  duct. 

The  muscles.  The  optic  nerve. 

9.  The  eyeball  is  like  the  box  that  the  photog- 
rapher uses  in  taking  your  picture.  In  the  front 
part  of  his  box  there  is  a  lens,  as  there  is  in  the 
eyeball.  In  the  back  part  there  is  a  plate,  which 
is  like  the  retina;  and  on  this  the  picture  is  made. 
When  you  look  at  an  object,  a  picture  of  it  is 
made  on  the  retina.  The  retina  is  the  end  of 
the  optic  nerve.  The  impression  which  makes  the 
picture  is  carried  by  the  optic  nerve  into  the  brain. 
It  is  really  the  brain  which  sees,  not  the  eye.  The 
eye  is  the  instrument. 

1C.  Good  eyes  do  not  often  get  tired,  and  they 
see  distinctly  both  far  and  near  objects.  Old  per- 
sons can  not  see  things  near  their  eyes  so  dis- 
tinctly as  they  can  see  things  at  a  distance. 
Glasses  help  them  to  read.  Some  young  persons 
can  not  see,  distinctly,  things  a  little  way  off, 
though  they  can  see  perfectly  any  thing  very 
near  their  eyes.  We  call  them  near-sighted.  They 
sometimes  have  to  wear  glasses. 

CARE    OF   THE    EYES. 

11.  If  we  do  not  wish  to  become  near-sighted, 


THE    EAR. 


123 


or  to  have  weak  eyes,  we  should  observe  the  fol- 
lowing rules:  — 

(1.)  Do  not  hold  your  book  too  near  to  your 
eyes. 

(2.)  Do  not  hang  your  head  over  your  book. 

(5.)  Do  not  read  when  lying  down. 

(4.)  Do  not  read  when  the  light  is  growing  dim. 
Lay  down  your  book  until 
lamps  are  brought. 

(5.)  Stop  reading  when 
your  eyes  smart  or  feel 
tired. 

THE    EAR. 

SECT.  III. — 1.  You  know 
very  well  that  the  ear  is  not 
all  on  the  outside  of  the 
head.  The  part  which  you 
see  is  the  external  ear.  It 
is  the  end  of  a  tube,  which 
catches  the  sounds,  and  car- 
ries them  into  the  head. 
This  tube  is  an  inch  long, 
is  the  tympanum,  or  drum-head. 

2.  The  middle  ear,  or  drum,  is  behind  the  tym- 
panum. It  is  a  small  cavity,  which  contains  the 
little  bones  of  the  ear.  It  is  connected  with  the 
throat  by  a  tube  called  the  Eustachian  tube. 


Fig.  32. 

THE  EAR.  —  1 .  Parts  of  the  exter- 
nal ear.  2.  Parts  of  the  miudle 
ear.  3.  Parts  of  the  Internal  ear. 

At  the  bottom  of  it 


124  PHYSIOLOGY    PRIMER. 

3.  The  internal  ear  is  still  farther  in.  It  is  in 
this  part  of  the  ear  that  the  nerves  of  hearing  are. 
The  external  and  middle  ear  carry  the  sound  in. 
The  internal  ear  receives  it,  and  the  impression  is 
carried  from  there  in  to  the  brain. 

EFFECTS    OF   ALCOHOL   AND   TOBACCO. 

SECT.  IV.  —  1.  Alcohol  acts  very  quickly  upon 
the  whole  system.  When  men  take  a  little  it 
stimulates  the  nerves  and  brain.  If  they  take 
enough  to  get  slightly  intoxicated,  they  become 
talkative  and  boastful,  or  cross  or  silly.  If  they 
drink  more,  they  lose  their  judgment.  They 
are  ready  to  be  excited  by  small  things,  and  to 
quarrel.  Many  of  the  murders  and  other  crimes, 
of  which  we  read  every  day  in  the  papers,  are 
done  under  the  influence  of  alcohol.  Men  who 
when  sober  are  quiet  and  kind,  are  changed  by 
it  into  wild  beasts.  After  the  drunken  fury  is 
past,  they  are  filled  with  remorse  for  what  they 
have  done.  The  brain  ought  to  be  the  master  of 
the  whole  body.  In  such  men  it  becomes  a  slave. 
When  the  appetite  sends  in  through  the  nerves 
a  demand  for  liquor,  it  can  not  refuse. 

2.  The  man  who  indulges  freely  in  drink  is 
likely  to  pay  for  it  the  next  day.  His  head  aches. 
He  is  low-spirited  and  weak.  His  stomach  is  foul. 


EFFECTS   OF  ALCOHOL   AND    TOBACCO.  125 

His  appetite  is  gone.  He  then  thinks  that  he 
never  will  take  it  again.  But,  when  the  nerves 
are  accustomed  to  the  excitement  of  drinking, 
they  will  not  give  it  up  easily. 

3.  Delirium  tremens  is  one  of  the  results  of  the 
free  use  of  alcohol.     This  is  a  disease  of  the  ner- 
vous system.     The  victim  of  it  is  wild  and  raving. 
He  is  filled  with  distress  and  horror.     Death  some- 
times ends  his  misery.     If  he  recovers,  he  is  likely 
to  have  it  again  if  he  continues  drinking. 

4.  Insanity  is  another  result  of  drinking-habits. 
Many  of  the  patients  in  insane-asylums  are  brought 
there  by  drink. 

5.  Discord  in  families,  quarrels,  murders,  sick- 
ness, pauperism,  insanity,  and  misery  are  some  of 
the  results  of  the  action  of  alcohol  on  the  nervous 
system. 

Do  not  understand  that  alcohol  always  pro- 
duces such  results.  Men  sometimes  use  it  through 
a  long  life  without  seeming  to  be  harmed  by  it. 
But  its  victims  are  in  every  community,  and 
among  all  classes  of  the  people. 

6.  Tobacco  acts  on  the  nervous  system  chiefly. 
At  first  it  makes  the  head  giddy,  and  the  whole 
body  faint  and  sick.     Afterwards  it  gives  pleasure. 
An  unsteady  hand,  a  languid  brain,  and  an  irregu- 
lar heart,  often   follow  its  use.      Many  men  are 


126  PHYSIOLOGY    PRIMER. 

wearing  out  their  nerves,  and  shortening  their 
lives,  by  tobacco.  Many  boys  are  making  their 
bodies  puny,  and  their  minds  weak,  by  tobacco. 

Cigarettes  are  said  to  have  a  worse  effect  on  the 
nervous  system  than  cigars.  Sometimes  they  are 
made  of  the  stumps  of  cigars,  which  contain  more 
nicotine  than  other  tobacco;  and  their  smoke  is 
more  likely  to  be  drawn  into  the  lungs. 

7.  Opium  and  chloral  are  used  for  their  effects 
on  the  nervous  system.  Their  habitual  use  tends 
to  destroy  the  will-power  and  the  conscience,  and 
ruin  the  mind  altogether. 


QUESTIONS. 

SECT.  I.  —  1.  What  is  it  to  feel  nervous? 

Why  does  a  drunken  man  fall? 

2,  3.  Where  is  the  brain?  Of  what  color  is  it?  What  animals 
have  the  largest  brains?  Where  are  thinking,  willing,  and  remem- 
bering done?  How  do  you  know?  Why  should  we  expect  man's 
brain  to  be  larger  than  the  brains  of  lower  animals  ? 

4-7.  What  is  the  spinal  cord?  Where  is  it?  What  are  the 
nerve-centers?  What  are  the  nerves?  With  what  are  they  all  con- 
nected? Where  is  the  olfactory  nerve?  the  optic  nerve?  the  au- 
ditory nerve?  Where  do  the  nerves  from  the  spinal  cord  go? 

8.  How  large  is  the  largest  nerve?  the  smallest? 

9.  Describe  the  course  of  a  nerve  starting  from  the  backbone. 
Why  does  your  little  finger  tingle  when  you  strike  your  "funny- 
bone?" 

11-15.  What  are  telegraph-wires  for?  How  does  the  nervous 
system  resemble  the  telegraph?  Give  illustrations.  What  happens 


QUESTIONS.  127 


when  we  see  or  hear  or  smell  or  taste  or  touch  any  thing?  What  is 
it  to  be  paralyzed?  Could  we  feel  or  move  without  the  brain  and 
nerves  ^/ 

16.  /Why  is  fresh  air  needful  for  the  brain?  Why  is  muscular 
exercise  needful  for  the  brain?  What  happens  to  the  brain  and 
nerves  if  we  do  not  have  food  enough,  or  if  we  spoil  our  digestion? 

Wiry  is  sleep  needful  for  the  brain  and  nerves? 

Why  do  children  need  more  sleep  than  grown  people?  Why 
is  change  of  occupation  needful  for  the  brain  and  nerves? 

SECT.  II.  — 1-11.  What  is  the  cavity  in  which  the  eye  is  situated 
called?  What  is  the  lachrymal  gland?  What  is  its  use?  Where 
is  the  lachrymal  sac?  Where  is  the  nasal  duct?  What  makes 
tears?  What  is  the  pupil  of  the  eye?  What  is  the  iris?  What  is 
its  use?  What  is  the  cornea?  What  is  the  sclerotic  coat?  What 
do  the  muscles  of  the  eye  do?  Where  does  the  optic  nerve  enter 
the  eye?  What  is  the  retina?  What  is  contained  in  the  eyeball? 
Name  the  principal  parts  of  the  eyeball.  Name  the  principal  parts 
of  the  eye  outside  of  the  eyeball.  What  instrument  is  the  eyeball 
like?  For  what  do  old  persons  need  glasses?  What  is  it  to  be 
"  near-sighted  "?  Give  some  rules  for  the  care  of  the  eyes. 

SECT.  III.  — 1-3.  What  do  you  call  that  part  of  the  ear  which  is 
on  the  outside  of  the  head?  Where  is  the  Eustachian  tube?  What 
is  in  the  internal  ear? 

SECT.  IV.  —  1.  What  is  the  effect  of  a  small  amount  of  alcohol 
on  the  nervous  system?  What  is  the  effect  of  a  larger  amount? 
How  does  alcohol  enslave  the  brain? 

2-4.  What  is  often  the  effect  of  the  free  use  of  alcohol  on 
the  nervous  system  the  day  after  taking  it?  What  diseases  of  the 
nervous  system  result  from  the  use  of  alcohol? 

5.  What  other  results  of  the  action  of  alcohol  on  the  nervous 
system?    Do  these  results  always  follow? 

6,  7.  What  effect  does  tobacco  often  have  on  the  nervous  sys- 
tem?   Are  cigarettes  less  harmful  than  cigars?    What  is  a  common 
effect  of  the  habitual  use  of  opium  and  chloral? 


Parietal. 


Orbit, 


Inferior  Maxillary. 

Cervical  Vertebrae. 
Scapula. 


Humerus.. 


Lumbar  Vertebrae. 


Carpus. 
Metacarpus. 


Tibia. 
Fibula. 


Temporal. 


Clavicle. 


.Innominate. 


Pelvis. 


Patella. 


Tarsus. 
^--' 
•'''   .Metatarsus, 

••'"'  .  Phalanges. 


Fig.  33. 


TUE    FRAMEWORK. 


129 


CHAPTER  X. 


THE    FRAMEWORK, 

SECT.  I.  —  1.  Thus  far  we 
have  been  studying  the  soft 
parts  of  the  body.  When  they 
are  taken  away,  the  bony  frame 
remains. 

A  skeleton  is  a  ghastly  ob- 
ject.   But,  if  you  had  no  bones     * 
under  your  flesh,  you   could 
not  walk,  or  even  stand.     The     § 
skeleton    protects    the    brain     |    3 
and  the  spinal  cord,  and  the     ^   '„ 
heart    and    lungs,  and   other     3 
parts,  in  its  cavities.  ~ 

2.  Man  and  the  quadrupeds,     | 
and   birds  and  fishes,  are  all     f 
alike   in  this:   they  all   have 
bony   frames,   and    all    have 
backbones.      The    backbone    is 
made  up  of  small  bones  called 
vertebrae;   and   man,  and   all 
animals  with  a  backbone,  are 


130 


PHYSIOLOGY    PRIMER. 


called  vertebrates.  Their  bony  frames  are  a  good 
deal  alike  too.  The  skeleton  of  a  cat  has  the 
same  parts  as  that  of  a  man.  Her  fore-legs  corre- 
spond to  his  arms.  Her  backbone  is  lengthened 
out  in  a  tail.  Her  claws  correspond  to  his  finger* 
nails. 

3.  A  child  has  many  more  bones  than  a  man, 
because  some  bones  that  were  at  first  separate  grow 
together  as  he  gets  older.     A  man  has  two  hundred 
bones. 

4.  Some  of  the  bones  of  the  skull  are  flat.     The 
ribs  are  flat  and  curved.     The  hip-bones  are  very 

irregular  in  shape.  The 
bones  of  the  limbs  are 
long  and  rodlike. 

5.  The  vertebras  which 
make  up  the  backbone 
are  bound  together  by 
strong  ligaments.  They 
move  a  little  on  each 
other;  and  so  the  back- 
bone can  be  bent  and 
twisted  in  every  direction,  and  serves  us  much 
better  than  it  would  if  it  were  all  one  stiff  bone. 
In  every  vertebra  there  is  a  large  hole.  When 
they  are  joined  together,  these  holes  make  a  canal 
in  the  center  of  the  backbone,  which  is  called  the 


Fig.  35. 

A  VERTEBRA. —  1.  Body.   2.  Processes. 
3.  Spinal  canal. 


THE  FRAMEWORK. 


131 


spinal  canal.  The  top  vertebra  fits  around  a  hole 
in  the  bottom  of  the  skull.  Through  this  hole, 
the  spinal  canal  connects  with  the  cavity  of  the 
skull. 

The  top  vertebra  is  called  the  atlas.  You  can 
easily  find  the  reason  for  this  name  by  inquiring 
of  your  teacher. 

6.  The  spinal  cord  is  well  protected  by  the  back- 
bone, and  the  brain  is  well  protected  by  the  skull. 


Fig.  36. 


THE  SKULL. —1.  Frontal  bone.  2.  Parietal  bone.  3.  Occipital  bone.  4.  Temporal 
bone.  5.  Nasal  bone.  6.  Malar  bone.  7.  Superior  maxillary  bone.  8.  Lachrymal 
bone.  9.  Inferior  maxillary  bone. 

The  only  openings  in  the  skull  are  the  large  one 
which  connects  its  cavity  with  the  spinal  canal, 
and  the  small  ones  which  let  the  nerves  through. 

7.  The  ribs  are  twelve  in  number  on  each  side. 
The  first  seven  of  these  are  connected  with  the 


132 


PHYSIOLOGY    PRIMER. 


Shoulder.-""} 


Arm. 


backbone  behind  and  the  breast-bone  in  front.* 
These  are  called  true  ribs.  Five  are  not  connected 
with  the  breast-bone.  They  are  called  false  ribs. 

The  collar-bone  and  the 
shoulder-blade  form  the  shoul- 
der. 

The  arm  (from  shoulder  to 
elbow)  has  one  bone. 

The  fore-arm  (from  elbow  to  hand) 
has  two  bones. 

The  hand  (including  the  wrist)  has 
twenty-seven  bones. 

The  two  hip-bones  are  very  large 
and  strong.  The  thigh  has  one  bone, 
which  is  the  largest  in  the  body. 

The  knee-cap  is  a  small  bone  in 
front  of  the  knee. 

The  leg  (from  knee  to  foot)  has 
two  bones. 
The  foot  has  twenty -six  bones. 


Hand. 


Fig.  37. 
The   Upper  Limb. 


JOINTS. 

SECT.  II. — 1.  All  these  bones  are  connected  by 
joints.  Some  of  them  are  called  hinge-joints,  be- 
cause they  allow  movement  in  two  directions,  like 
a  hinge.  The  elbow-joint  is  a  hinge-joint.  Others 


For  representation  of  the  Thorax,  see  Fig.  25. 


JOINTS. 


133 


Thigh. 


are  called  gliding  joints,  because  the  bones  glide  on 
each  other  in  various  directions.  The  wrist-joint 
is  a  gliding  joint.  The  shoulder  and 
the  hip  joints  are  called  ball-and- 
socket  joints.  They  allow  motion  in 
every  direction,  and  are  the  freest  of 
all  the  joints. 

In  a  movable  joint,  the  bones  are 
covered  with  cartilage  (gristle),  Car- 
tilage is  smooth,  and  more  elastic 
than  bone.  It  makes  the  joints 
springy. 

Most  of  the  joints  in  the  skull  are 
tight  and  immovable. 

2,  In   every  machine,   the  joints 
have   to   be   carefully  watched,  and 
greased  often,  or  else  they  will  get 
dry,  and  creak  and  wear.    Our  joints 
grease  themselves.     They  have  a  lin- 
ing, that  keeps  giving  out  from  its 
surface  a  fluid  like  the  white  of  an 
egg.      This  fluid  is  called  synovia, 

or  joint-water.  Unless  we  have  rheumatism,  or 
some  other  disease  of  the  joints,  they  are  kept 
always  smooth,  and  in  good  working-order,  in  this 
way. 

3.  The  bones  are  held  together  at  the  joints  by 


Leg. 


Foot. 


Fig.  38. 

The  Lower  Limb, 


134 


PHYSIOLOGY    PRIMER. 


bands  of  strong,  tough  substance  that  does   not 
stretch.     These  bands  are  called  ligaments,  and 

they  surround  the  ends 
of  the  bones.  Sometimes 
a  bone  gets  such  a  twist 
that  the  end  of  it  breaks 
through  the  ligaments, 
and  gets  out  of  joint. 
Then  it  must  be  carefully 
put  in  place. 

STRUCTURE    OF    BONE, 

SECT.  III.  —  1.  Bones 
Fig.  39.  that    have     been    thor- 

JOINTS    OF    THE    SKULL.  - 1.  Frontal  1    1  1     -       1  f  ^  ,-,  f 

bone.     2.  Parietal  bone.     3.  Occipital      '  )Ugmy  'Q> 

bone  have    been    cooked,  are 

white.  But  a  bone  in  a  living  person  is  pink  in 
color.  It  is  full  of  blood-vessels,  and  has  nerves 
too.  It  is  made  partly  of  phosphate  of  lime, 
which  is  a  mineral  just  like  some  rocks.  That 
is  what  gives  it  its  hardness.  Children's  bones 
tire  not  so  brittle  as  those  of  grown  people 
Vhey  will  bend  a  good  deal  without  breaking. 
The  bones  of  old  people  are  sometimes  very 
brittle. 

2.  The  long  bones  are  not  solid,  but   have  a 
canal  in  their  centers.     This  is  filled  with  marrow. 


CARE   OF  THE    FRAME. 


135 


If  you  cut  through  a  flat  bone,  you  will  find  that 
it  is  hard  outside,  but  inside  it  is  full  of  holes, 
which  give  it  a  kind  of  honeycombed  appear- 
ance. 

3.  When  a  bone  is  broken,  it  has  to  be  "  set." 
In  setting  bones,  the  broken  ends  must  be  fitted 
together.  Bandages, 
and  strips  of  wood, 
or  some  stiff  sub- 
stance, must  be  put 
around  them,  to  keep 
them  in  place.  Then 
Nature  joins  them  so 
that  they  are  just  as 
strong  as  before. 


Innominate. 


CARE    OF    THE     FRAME. 


Femur 


Fig.  4O. 
The  Hip -Joint. 


SECT.  IV.  —  1.  Some  peo- 
ple have  better  forms  than 
others.  The  form  depends 
chiefly  on  the  bony  frame.  A  straight  back 
and  neck,  and  a  full  chest,  a  waist  of  natural 
size,  and  straight  limbs,  make  a  good  figure 
The  shape  we  shall  have  when  we  are  grown 
depends  very  much  on  our  habits  while  we  are 
children. 

2.  If  we  sit  or  stand  with  our  shoulders  for- 


136 


PHYSIOLOGY    PRIMER. 


ward,  and  our  backs  curved,  we  shall  be  likely  to 
have  curved  backs  and  stooping  shoulders  always. 
If  we  hold  up  our  heads  and  shoulders,  our  backs 

will  grow  straight. 

3.  The  part  of  our  frames 
which  is  most  frequently 
misshapen  is  the  foot.  We 
can  change  the  shape  of  the 
foot  very  much  by  the  shoes 
we  wear.  The  great  toe  is 
naturally  almost  in  line  with 
the  inner  side  of  the  foot, 
and  the  other  toes  are  spread 
out  so  as  to  have  plenty  of 
room.  But  the  great  toe  of 
most  grown  people  turns  in 
toward  the  other  toes,  and  the  toes  overlap  each 
other.  Short  and  narrow  shoes,  and  high  heels, 
have  caused  this.  The  swelling  on  the  great-toe 
joint,  which  is  called  a  bunion,  is  made  in  the  same 
way. 

4.  Tight  and  high-heeled  shoes  check  the  nat- 
ural elastic  movements  of  the  foot,  and  deform  it. 
Clothes  which  bind  the  waist  and  chest  hinder 
breathing,  and  squeeze  the  inward  parts  out  of 
place. 

The  frame  should  be  free  in  every  part  to  take 


Fig.  41. 
The  Shoulder- Joint. 


QUESTIONS.  137 


Fig.  42. 

Section  of  the  Thigh- bone. 

the  shape  which  Nature  intended  for  it.     Active 
exercise  of  the  muscles  helps  it  to  do  so. 

EFFECTS    OF    ALCOHOL    AND    TOBACCO. 

SECT.  V.  —  1.  The  bones  are  alive  as  truly  as 
are  the  soft  parts  of  the  body.  The  blood  runs 
through  them  constantly.  They  depend  on  it  for 
their  nourishment  and  health.  When  the  blood 
is  poisoned  with  alcohol  and  tobacco,  and  the  rest 
of  the  system  is  suffering,  the  bones  must  suffer 
too. 

2.  There  is  good  reason  for  believing  that  boys 
frequently  check  the  growth  of  their  bony  frames  by 
the  use  of  alcohol  and  tobacco. 


QUESTIONS 

SECT.  I.  —  1.  Of  what  use  is  the  hony  frame  in  the  body? 
2.  What  is  a  vertebra?    What  is  a  vertebrate?     What  animals, 
with  which  you  are  familiar,  are  vertebrates? 


138  PHYSIOLOGY   PRIMER. 

3,  4.  Who  has  the  largest  number  of  bones,  —  a  child  or  a  man  ? 
How  many  bones  has  a  man?  What  are  the  shapes  of  the  bones? 

5.  What  makes  the  backbone  flexible?    What  makes  the  spinal 
canal?    How  does  the  spinal  canal  connect  with  the  cavity  of  the 
skull?    \\  hy  is  the  top  vertebra  called  the  atlas? 

6.  How  is  the  spinal  cord  protected?    The  brain? 

7.  How  many  ribs  are  there?    Which  are  the  true  ribs?    Which 
are  the  false  ribs?    With  what  are  the  true  ribs  connected?    With 
what  are  the  false  ribs  connected?    What  bones  form  the  shoulder? 
How  many  bones  in  the  arm?     How  many  bones  in  the  fore-arm? 
How  many  bones  in  the  hand?    How  many  bones  in  the  thigh? 
What  is  the  knee-cap?    How  many  bones  in  the  leg?  in  the  foot? 

SECT.  II.  —  1.  How  are  the  bones  connected?  Name  three  kinds 
of  joints,  and  mention  one  of  each  kind.  What  joints  allow  the 
freest  motion?  What  covers  the  bones,  in  a  movable  joint?  What 
is  the  use  of  this  covering?  Are  all  the  joints  movable? 

2.  How  are  our  joints  kept  smooth  ?     Do  they  ever  get  rough? 

3.  What  holds  the  bones  together  at  the  joints  ? 

SECT.  III.  —  1.  What  is  the  color  of  bone?  Has  bone  any  blood- 
vessels ?  What  makes  bones  so  hard?  What  difference  is  there 
between  the  bones  of  children  and  grown  people? 

2,  3.  Are  the  long  bones  solid?  What  is  in  them  ?  Are  the  flat 
bones  solid?  Why  not?  What  must  be  done  with  a  broken  bone  ? 
What  does  Nature  do  with  it? 

SECT.  IV. — 1-3.  What  gives  shape  to  the  human  form  ?  What 
do  we  mean  by  a  good  figure  ?  How  may  our  figures  be  made  better 
or  Averse  ?  What  part  of  our  frames  is  most  often  misshapen? 
How  is  it  made  so?  What  is  a  bunion? 

4.  What  is  the  effect  of  tight  and  high-heeled  shoes?    What 
is  the  effect  of  tight  clothing  about  the  waist  and  chest?    What 
helps  the  frame  to  take  a  good  and  natural  shape? 

SECT.  V.  —  1.  How  may  alcohol  and  tobacco  affect  the  bones? 
2.  How  may  they  affect  the  size  of  the  body  ? 


SUPPLEMENTARY    CHAPTER, 
GLOSSARY,  AND    INDEX. 


STIMULANTS  AND  NARCOTICS.  139 


SUPPLEMENTARY   CHAPTEE. 


STIMULANTS    AND    NARCOTICS. 
DRINKS. 

SECT.  I.  —  1.  Fluids  are  needed  in  the  human 
body  for  the  reason  that  they  convey  to  the 
different  organs  just  the  matter  they  need  for 
building  them  up,  and  take  away  the  worn-out 
and  cast-off  particles,  acting  as  a  go-between  or 
common  carrier,  in  the  processes  of  digestion 
and  nutrition.  The  larger  part  of  the  fluids 
taken  into  the  system  is  in  the  form  of  drinks. 
The  chief  drinks  used  by  mankind  are  water, 
milk,  tea,  coffee,  cocoa,  and  various  intoxicating 
liquors. 

2.  Milk  carries  the  natural  food  of  mankind 
before  the  teeth,  which  form  the  machine  for 
chewing,  are  furnished.  We  say,  therefore,  that 
milk  is  a  food  because  it  always  contains  certain 
things  which  build  up  and  sustain  the  body. 
Other  drinks  may  or  may  not  contain  such  sub- 
stances. They  may  have  in  them  food,  juices, 
or  flavors,  in  which  case  they  are  the  carriers 
of  those  foods,  juices,  or  flavors  to  the  human 
system. 

J  - 

OF  TUB 


frrfrL.,     s 


140  PHYSIOLOGY  PEIMEE. 

3.  But  if  we  get  juices  in  liquids  we  also  get 
a  part  of  our  natural  water  supply  from  the 
grains,  vegetables,  meats,  and  fruits  which  we 
eat,  as  well  as  from  the  spring,  the  brook,  or 
the  river. 

TEA,    COFFEE,    AND    COCOA. 

SECT.  II.  —  1.  Although  these  three,  tea,  coffee, 
and  cocoa,  should  be  studied  separately,  they 
are  so  much  alike  in  some  respects  that  we  may 
arrange  them  side  by  side  as  we  consider  them 
here.  There  is  one  element  that  is  found  in 
them  all,  arid  it  is  on  account  of  this  one 
element,  or  ingredient,  principally,  that  people 
acquire  the  habit  of  using  them. 

2.  This  important  element,  which   causes  the 
habit  of  using  tea,  coffee,  or   cocoa,  is  so  impor- 
tant that  we  will  call  it  the  essential   principle 
in  each  of  these.     But,  although  it  is  present  in 
each,  it  is  not  called  by  the  same  name  in  each 
case ;    for  it  is  changed  by  the    other   substances 
with  which  it.  is   combined.      In  tea  it  is  called 
theine;  in  coffee,  caffein;  in  cocoa,  theobromine. 

3.  Tea  contains  almost  no  oil  or  fat;    but  in 
coffee  they  are   about   one-eighth   of  the  whole ; 
while  cocoa  is   about  one-half  oil   or   fat.      An- 
other important  part  of  food  is  sugar,  or  starch 
which  can  be  changed  to  sugar.      In  examining 
any  article   of  food  or  drink,   therefore,    we   al- 


STIMULANTS  AND  NARCOTICS.  141 

ways  inquire  about  the  sugar  it  contains.  On 
analyzing  tea  it  has  been  found  that  it  has  no 
sugar;  while  in  coffee  nearly  one-sixth  of  the 
whole  is  sugar  or  something  which  may  become 
sugar;  and  cocoa  has  less  than  half  as  much 
of  such  substances  as  coffee  has. 

4.  These  drinks  have  very  little  else  in  them 
which  can  build    up    the   system    or    answer  for 
the  purposes  of  food.     The  addition  of  milk  and 
warmth   to   either   one   increases   its   value  as  a 
food. 

PECULIAR   EFFECTS   OF  TEA,   COFFEE,   AND   COCOA. 

5.  The    fragrance   or   smell  of  a    substance  is 
called    its    aroma.     Now    it   is   the   aroma    and 
the  effects  of  their  essential  principle,  of  which 
we    have    spoken,    that     cause    us   to    use    tea, 
coffee,  and  cocoa.     By  experimenting    with    the 
essential  principle  of  each,  men  have  found  out 
much    about   their   peculiarities,  and   they    have 
learned  that  all    three    have  a  stimulating    and 
restorative  effect  on  the   nervous  system.     They 
have    also     found    that   their    action    is    always 
helped  a  little  by  warmth. 

6.  All  these   drinks  are    somewhat  antiseptic; 
that  is,  they  have  a  tendency  to   prevent  decay; 
an  article  placed  in  either  of  them  is  preserved 
for  a  time. 


142  PHYSIOLOGY  PRIMER. 

7.  Tea  increases  the  action    of  the   skin   and 
causes  the  kidneys  to  secrete  more  water. 

8.  Coffee,  perhaps  on  account  of  the  essential 
oil  it  contains,  is  more  stimulating  to  the  nerves, 
but  the  refreshing  effect   of  tea  is   more   lasting. 
There  is  very  little  if  any   reaction  from   either. 
If  the   essential   principle   of  coffee  be  given    in 
full   doses   to   animals    it   will    cause    trembling 
and  stiffness  of  the  muscles. 

9.  While  we  can  analyze  a  substance  and  tell 
what  it  contains ;    and  while  we  may  be  able  to 
say  what  its  general  effect  is  upon  a  person,  yet 
people  differ  so  much  that  it  is  not  strange  that 
the  same  article  of  food  or  drink  acts  on  differ- 
ent persons  somewhat  differently.      Therefore   to 
tell  how  tea  and  coffee  affect  different  individu- 
als we  must  observe  them  closely.     These  drinks 
are  not  to  be  taken  as  foods,  in  the  usual  sense 
of  the    word,  and,    therefore,    we    should    watch 
narrowly  their  effects  on  ourselves  or  others   to 
judge  of  the   extent   to    which    it    is    proper   or 
safe  to  use  them  in  any  case. 

1C.  It  is  true  that  the  effects  of  all  such  stimu- 
lants or  articles  which  act  on  the  nerves  are 
modified  by  their  being  taken  while  the  stomach 
is  nearly  empty  or  sometimes  after  eating.  It 
is  generally  better  to  take  them,  if  at  all,  while 
eating. 


STIMULANTS  AND  NARCOTICS.  143 

11.  Certain  portions  of  milk,  when  used  in  tea, 
unite  with   the  tannic  acid  in  the  tea  and  form 
a  compound  which    is   difficult   to   dissolve,  and, 
therefore,  to   digest.     When    tea    and    milk    are 
taken     in     large     quantities     they    weaken    the 
digestive    powers.      It    is    for    this    reason    that 
cream   is   much   better   than    milk   in   tea. 

12.  The  tannin  in  tea,  whether  with  or  with- 
out milk,  makes  it  far  from  beneficial,  and  it  is 
usually  a  hindrance  rather  than  an  aid  to  diges- 
tion.    As     we    have    seen,  it    contains    no    food 
element,  and,  therefore,  except   for   its  effects  on 
the  nerves,  it  may  well  be  left  off  our  tables. 

13.  Children   are    better    off    without   tea   or 
coffee ;   but   for   some    a  warm    fluid    with    theii 
meals  is  better   than    cpld    water.     When  such  a 
drink    is    needed,  very    hot   water    cooled    suffi- 
ciently to  drink,  with  milk,  and  sweetened  with 
sugar  will  be  found  very  good. 

14.  While  tea  and  coffee    are    open    to   many 
objections     as     beverages,    particularly     for    the 
young,  these  do  not  apply  to  cocoa.     Cocoa  con- 
tains  so  large  a  proportion  of   fat  and  of   other 
nourishing   substances   that   it   has  a  real    value 
as  a  food.     The  cocoa  beans,  or  seeds,  are  roasted 
and    then    passed     through    a    machine     which 
loosens   their   outer   coat   or   husks,    when   these 
are  separated   leaving   the   nibs   or   inner   pieces 


144  PHYSIOLOGY  PRIMER. 

ready  for  market.  The  starch  which  the  seed 
contains  has  been  changed  into  a  sort  of  sugar 
by  the  roasting,  and  this  is  what  gives  it  one 
of  its  most  important  food  qualities. 

15.  Owing    to    the    fact    that    the    cocoa  con- 
tains so  much   fat  and   starch    when   it   is   pure, 
dishonest   persons   adulterate   it   by  the  addition 
of  fat  and    starch  not    found    in  the  pure  fruit; 
and    among    the    many    forms   of    adulteration 
this    is   one    of    the    most    objectionable.     Some 
find  even  the  natural  amount  of  fat   too   much, 
and    so    now    much   of   this   is    removed    and   is 
used    for  other  purposes  besides    food,  under  the 
name   of   cocoa  butter.      Since    the    fat  of    the 
cocoa  is  not  essential,  enough  of  such  substance 
being    found    in    other   articles    of    food,    it    is 
better   to   get   the   cocoa    prepared    without    the 
oil.      Such     preparations     may    now    be    found 
with  the  best  grocers,  and  when  properly  served 
they    make    an    excellent    drink.      Cocoa,    well 
prepared    for    the   table,  deserves   to   come   into 
much   more   general   use,  and    would    be   found 
better    and    more    healthful    than    the   tea  and 
coffee   now   so   commonly   drank. 

16.  The    drinks    we    use    have   so    much    to 
do  with  our  health,  and  with  that  vital  strength 
Ave    need    for   study    or   other    work,   that   it    is 
very    important    that    we    learn    the    effects   of 


STIMULANTS  AND  NARCOTICS.  145 

different  drinks,  and  decide,  early  in  life,  what 
ones  are  safest  to  use  and  which  to  avoid. 
Our  habits  should  be  based  on  sound  judg- 
ment and  information ;  and  any  habit  which 
does  not  commend  itself  to  our  best  judg- 
ment should  never  be  formed,  or,  if  formed, 
promptly  discarded. 

17.  While  tea  and  coffee  are  often  drank  to 
excess,  and  many  habitually  use  them  too 
freely,  their  moderate  use  is  based  on  very 
different  grounds  from  that  of  some  other 
drinks. 

ALCOHOLIC     DRINKS. 

SECT.  III. — 1.  It  is  very  important  that  every 
person  should  know  the  relation  that  fluids 
containing  alcohol  bear  to  foods,  and  to  individ- 
ual and  public  health.  The  mind  and  morals 
affect  the  welfare  of  the  body,  and  therefore 
we  cannot  overlook  the  effects  of  such  fluids 
on  these.  If  they  lead  to  the  formation  of 
habits  which  impair  the  health;  or  if  they 
make  one  less  able  to  exercise  self-restraint  or 
self-control, — for  these  powers  form  the  basis  of 
health  and  character,  —  then  the  young  should 
be  instructed  and  impressed  with  the  danger  of 
their  use,  and  this  should  be  done  so  early  in 
life  as  to  come  before  the  formation  of  any 
habits  which  might  not  be  broken  off. 


146  PHYSIOLOGY  PRIMER. 


ALCOHOL. 

2.  Spirituous  liquors  differ  among  themselves 
in  many  respects,  but   they  all   depend  for  their 
use  as  beverages  on  one  element  which  is  found 
in  them,  namely,  alcohol. 

3.  Alcohol  burns  freely  with  a  great  heat,  and 
evaporates  rapidly ;    it   may  therefore  be  defined 
as   that   inflammable,    volatile,    spirituous    liquid 
which    forms   the    essential    elements,    or    intoxi- 
cating principle  in  spirits,  wines,  and  beers. 

4.  Liquors    containing    alcohol    are    usually 
spoken  of  under  two  classes.     First,  those  which 
are    produced     by    fermentation,    or     fermented 
liquors ;   second,   those   produced   by   distillation, 
or     distilled      liquors.        Wine     and      beer     are 
fermented    liquors ;    brandy     and     whiskey    are 
distilled  liquors. 

5.  Fermentation   is  produced   from  the  juices 
of  fruits,  or  by  the   addition  of  water    to   grains 
treated     in    a    certain    way,    by    allowing    their 
starch    or    other    sugar-producing    substances    to 
decompose,  thus   setting   free  gases    and    forming 
new  compounds  unlike   the  original   liquid,  and 
containing  alcohol.     The   working   of  cider   is  a 
familiar  example  of  fermentation. 

6.  Distillation  is  brought  about   by   evaporat- 
ing  the  liquid    from    which   the  liquor  is  to   be 


STIMULANTS  AND  NARCOTICS,  147 

made,  and  condensing  the  steam,  produced  by 
the  heat  used  in  evaporation,  in  a  long  tube 
called  a  still.  Fermented  liquors  are  said  to  be 
fortified  when  some  distilled  liquor  has  been 
added  to  them  either  to  preserve  them  or  make 
them  more  intoxicating.  This  is  frequently 
done. 

WINES,   BEER,    BRANDY,   RUM,   WHISKEY,   AND   GIN. 

7.  Wines    contain   alcohol,  various  acids,  gly- 
cerine, and  a  little  albuminous  substance. 

8.  Beer  contains,  besides  its   alcohol,  carbonic 
acid,    certain    oils,    malt    extract,    with    a    little 
starch,   sugar    and    albuminous    substance,    hop- 
resin,  or  other  bitters,  and  various  salts. 

9.  Brandy  is  made  by  the  distillation  of  wine  ; 
or  artificially,   by    adding   various   substances   to 
alcohol. 

10.  Rum  is  made  by  distilling  molasses  which 
has  first  been  fermented,  or  from  the  juice  of  in- 
ferior kinds  of  sugar-cane. 

11.  Whiskey  is  usually  made  from  grains,  as 
corn,  rye,    etc.,    but   it   may  also   be  made   from 
vegetables  and  fruits. 

12.  Gin    is    made    by    diluting    alcohol    and 
adding  various  flavoring  extracts, 

13.  Any  of  these  liquors,  or  all  of  them,  can 
be  made  artificially  nearly  like ,  the   distillation. 


148  PHYSIOLOGY  PRIMER. 

In  fact,  names  may  not  represent  distinct  kinds 
of  liquors,  but  rather  skillful  combinations  of 
various  dealers. 

IS    ALCOHOL    VALUABLE    AS    A    FOOD? 

14.  It  can  be  safely  said  of  all  alcoholic  liquors 
that  there  is  nothing  in  them  so    valuable  as  to 
make   it  desirable  to  use  them    unless    it   be  for 
the    sake   of    the    alcohol    itself.      And    this,    of 
course,  should    not    be    used    unless    it    can    be 
shown  to  be  needed.      When  we    come   to  study 
the  relation  of  alcohol    to   foods  we  find  that  it 
is  never    found    in    nature ;    yet   all   such   foods 
as  are  necessary  to  maintain  life  and  health  are 
found  abundantly  'in    nature.      This    is    a   very 
suggestive  fact,  and  causes  us  to  wonder  why  it  is 
so,  if,  as  was    formerly    supposed,    alcohol    is    of 
great  value   as   a  food.      No    analysis    of    foods 
ever  finds  it  as  an  article  to  be  taken   into  the 
human    system.      If  it   has   any    such    value   as 
was   claimed,   this   seems   a    surprising   omission 
of  nature,  and  an  omission  not   at   all  in  keep- 
ing  with    her    ways    in    other    departments   of 
her   kingdom. 

15.  By  studying   the  physiology  of   digestion 
and  taking  up  of  foods    in    the   system    we    fail 
to  find    any    reason    for    supposing   alcohol    was 
ever  intended  to  be  used  as  a  food  by  mankind. 


STIMULANTS  AND  NARCOTICS.  149 

Formerly  this  was  not  thought  to  be  the  case, 
but  every  advance  in  chemistry,  and  every  ad- 
vance in  knowledge  of  the  relation  of  foods  to 
life  and  energy,  has  been  away  from  the  old 
idea  and  toward  the  view  here  taken,  that  alco- 
hol is  not  to  be  defended  on  the  ground  of  its 
food  qualities. 

16.  Toxic  is  the  Greek  word  meaning  poison. 
Persons  affected  by  alcohol  are  never  said  to  be 
over-fed,  but  to  be    intoxicated;  in    other    words, 
poisoned.     In  none  of  the  text-books  of  the  day 
on  chemistry  or  hygiene  is  alcohol   classed  as  a 
food. 

17.  Flesh-forming  foods,  because  they  contain 
much  nitrogen,  are  called  nitrogenous;  but  alco- 
hol contains  no  nitrogen,  and    hence   cannot    be 
called  a  flesh-forming  food. 

18.  But  another  class  of  foods  is   called  heat- 
producing.     Yet  although    it    burns  readily,  and 
gives  the  sensation  of  heat  in   the   stomach    and 
throat,  alcohol  reduces  rather  than  increases  the 
temperature.     It   does   not  produce   animal   force 
or   increase   animal  heat. 

WHAT    ALCOHOL    DOES. 

SECT.  IV. — 1.  We  have  explained  that  alcohol 
is  not  a  food,  but  on  the  contrary  a  toxic,  or 
poison.  We  have  shown  that  it  does  not  give 


150  PHYSIOLOGY  PRIMER. 

out  heat  to  the  body,  although  it  appears  to  do 
so.  What  then  does  it  do?  It  has  an  apparent 
effect  of  food.  In  other  words,  it  seems  to 
supply  the  food  at  first,  but  such  effects  soon 
depart,  leaving  the  system  still  more  in  want 
of  food  than  before  it  was  taken. 

2.  Alcohol,  like  opium,  chloral,  hasheesh,  and 
some   other   stimulants,  narcotics,  or    drugs,  acts 
upon  the  nerves  and  has  the  power  to  create   a 
habit  which  many  people  are  willing  to   under- 
stand as  a  natural  demand  of  the  system.     That 
is,  when  once  the  habit  of  using  alcohol  is  begun 
people    deceive    themselves    into    thinking    that 
they  must  continue  its  use  because  of  a  demand 
which  they  have   come  to  feel. 

3.  Remember    that    the     process     of    taking 
food  into    the    system,    and    converting    it    into 
tissue,  bone,  flesh,  and  sinew,  is  called  nutrition, 
and  it  is  with  nutrition   that  alcohol  principally 
interferes.     A  fact,  then,  to  bear  in  mind  is  that 
alcohol  and  alcoholic  drinks  interfere  with  nutri- 
tion. 

4.  These    articles    not    only    lack    any    food 
value   of   their    own,  but  they  take  away  a  part 
of  the  value  of  real  foods.     They  also  have  such 
an  effect  upon    the    organs  which  assimilate  and 
distribute  the    food    as    to   make   them    less  able 
properly  to  do  tneir  work.      So  that   they  inter- 


STIMULANTS  AND  NARCOTICS,  151 

fere  with  nutrition,  first,  by  taking  from  the 
value  of  the  foods  eaten,  and  second,  by  impair- 
ing the  usefulness  of  the  organs  which  take  up 
and  distribute  those  foods. 

5.  Science    formerly     taught    that     alcoholic 
drinks  were  not  only  valuable  as  foods,  but  very 
desirable  as   a  part  of  the    regular    food   supply, 
and  they  were  therefore  issued  as  a  part   of  the 
daily  rations  of  soldiers,  sailors,  and  other  persons 
engaged  in  constant  labor.      But  experience  has 
taught  that  such  a  use  of  them  not  only  fails  to 
serve  any  good  purpose,  but  actually  does  harm 
to  the  persons  taking   them. 

6.  What  experience  has  first  taught  science  is 
now  also  agreed  upon,  and,  by  applying  the  most 
careful  tests,  students  of  chemistry  and  of  physi- 
ology   have   found  that  experience   is   right,  and 
science,  until    recently,    has    itself    been    wrong. 
Now  both  science  and  experience  are  agreed. 

7.  It  often  happens  that  in  the  army  or  navy 
it  is  necessary  to  get  from  the  soldiers  or  sailors 
the  greatest  possible  amount  of  work  in  a  given 
time,  therefore   it   is   of  supreme   importance   to 
learn   exactly   what   foods  and   drinks  will   pro- 
duce  the    greatest    physical    endurance,    and    it 
is  on  this  test  that  alcohol  in  all  its  forms  has 
been  retired   from  the  service. 

8.  In  training  for   athletic   sports,  or  contests 


152  PHYSIOLOGY  PRIMER. 

of  all  sorts,  the  diet  is  very  carefully  guarded. 
Nearly  all  boys  who  read  of  athletic  contests, 
and  of  the  training  which  precedes  them,  must 
have  observed  that  alcohol,  as  well  as  tobacco 
and  other  narcotics,  are  rigidly  excluded. 

9.  Where  much  depends  upon  the  result 
of  these  contests,  not  only  on  account  of  the 
money  involved,  but  the  reputation  which  rests 
upon  the  winning  or  losing  of  the  prize,  the  fact 
that  a  person  likes  or  dislikes  any  particular 
food  or  drink  does  not  decide  him  as  to  its  use. 
Strong,  compact,  and  enduring  muscles,  with 
sound  lungs  and  perfect  circulation,  are  the 
qualities  desired,  and  all  athletes  have  learned 
that  these  cannot  be  obtained  by  indulging  the 
appetite  in  intoxicating  beverages. 

SOME   SERIOUS    FACTS. 

SECT.  V.  —  1.  The  accuracy  of  those  who  are 
opposed,  on  principle,  to  the  use  of  alcoholic 
beverages  is  sometimes  questioned,  when  they 
describe  the  ravages  of  diseases  caused  by  such 
drinks.  Feeling  the  evils  that  drinking  habits 
produce,  it  is  not  to  be  wondered  at  that  those 
who  labor  to  bring  about  better  habits  should 
speak  strongly,  but  the  most  careful  estimates 
drawn  from  statistics,  impartially  collected,  bear 
out  the  general  assertion  that  these  evils  are 
quite  as  bad  as  they  are  described. 


STIMULANTS  AND  NARCOTICS.  153 

2.  From     facts    gathered    between    the    years 
1870    and    1880,    in    England    and    Wales,    some 
startling  truths   are    learned.     First,  these  statis- 
tics   show    that    deaths    among    men    who    are 
directly  concerned    in   the  liquor  trade  are  very 
much  more  frequent   than  among  those  engaged 
in  other   occupations.     While    common    observa- 
tion   might    lead    one   to    the  same    conclusion, 
nothing    but    a    collection    of  ^  the    facts    them- 
selves,  for   a  period   of    years,  would   absolutely 
prove   it. 

3.  Life   insurance  tables,    prepared    with    the 
purpose   of    learning   whether   the   common   use 
of  stimulants  among   the   people  insured    would 
increase    the    risk    to    the    companies    insuring 
them,  prove  beyond   a   doubt   that   it   is   greatly 
increased,   the    risk    among    liquor-sellers    being 
shown   to   be   50  per   cent,   greater   than   among 
others. 

4.  Some    diseases   are   much    more     likely   to 
occur    with    persons    addicted    to    drink;    liver 
diseases,  for   instance, ,  being    six    times    as    pre- 
valent.    Without  here    specifying    other    diseases 
brought  about  in  the    same  way,  it  may  be  said 
that  there    is    scarcely    any    organ    of    the    body 
that  is  not   more    or    less    seriously  damaged  by 
the  excessive  use  of  alcoholic  drinks. 


154  rilYSWLOGY  PRIMER. 


EFFECTS    OF    MODERATE    DRINKING. 

5.  Many  persons    freely    admit    the    injurious 
effects  of  excessive  drinking,  but  are  not  willing 
to  believe  that  drinking  in  moderation  is  harm- 
ful.     Unfortunately    for   those    who    indulge    in 
this    delusion,  there    is    no   such   safety   as  they 
would  be  glad   to   suppose.      If  intoxicants    are 
habitually  taken,  even  in  small   quantities,   per- 
sons   addicted    even    to    such    moderate   use   of 
them   are    likely    to    suffer    from   hardening    of 
some  of  the  nerve-centers,  and   from   the   shriv- 
elling and   thickening  of  the  lining  membranes 
of  the   stomach. 

6.  The     kidneys     are     still     more     seriously 
affected,  being  very  susceptible    to    injury    from 
this  cause.     The  tendency  of  alcohol   to  distend 
and  engorge  the  minute  blood-vessels   is  plainly 
shown     in     the     reddened    face    and    unnatural 
complexion    of    many    persons    who,  while  they 
habitually  use  it    in    small    quantities,  may  not 
be  called  excessive  drinkers. 

7.  When  we   have    shown    that   the   stomach, 
the  liver,  and  the  kidneys  are    easily  affected  in 
a  serious    manner    by    drinking   habits   it  is  not 
necessary   to   go    further    and    specify   by   name 
the    various    forms    of    disease    which    are    often 
brought  about.      It  is  sufficient  to  say  that  they 


STIMULANTS  AND  NARCOTICS.  155 

are  many  and  are  of  very  frequent  occurrence, 
being  alarmingly  prevalent  among  the  class  of 
people  known  as  "  moderate  drinkers." 

8.  The   effects   of    alcohol    upon   the   nervous 
system,    brain,    and     mind     are     too     frequently 
shown    in    the    daily    walks  of   life  to  need  any 
extended     comment    here.      Any    one    who    has 
seen    a   drunken    man    in    all    his    repulsiveness 
needs   not  to   be  convinced   that  intoxication  is 
an    evil. 

9.  The    effects    upon    the    man    who     habit- 
ually  uses   liquor,  but    may   never    be    seen    in 
this    condition,  are   not   so   apparent,    and   it    is 
only    by    a    careful    observation    of    many   cases 
under     various     conditions    that    it     has     been 
proved   that   these    effects   are  just   as    real,  and 
as  certainly  harmful  as  drunkenness  itself. 

10.  With  alcohol  as  with  tobacco  the  opportu- 
nity  for   its   most    disastrous   effects   come   from 
its    tendency    to   create   an   appetite    and    habit. 
And    again,  as    in    the    case    of    tobacco,    those 
who  never  begin    its   use   never   regret   it,  while 
all    unite    in    deploring    its    evils   though    they 
themselves   may   be   its   victims. 

11.  No  one  becomes  a  drunkard,  or   a   victim 
to    the    tobacco    habit,     all     at    once.      No    one 
intends    to    become     so     when     he     begins    the 
use   of    either  of    these    dangerous    articles;    but 


156  PHYSIOLOGY  PRIMER. 

it  is  impossible  for  one  to  tell  where  the  habit 
may  lead  if  once  formed,  and  therefore  the 
only  wise  and  safe  course  is  never  to  form  it. 

12.  Touch  not,  taste  not,  handle  not,  is  a 
wise  maxim  to  follow,  not  alone  for  the  sake 
of  containing  one's  self-control,  but  as  a  safe- 
guard for  health. 

CONDIMENTS. 

SECT.  VII. —  1.  There  are  other  substances 
taken  into  the  mouth  which  cannot  be  classed 
as  foods,  although  they  have  some  relation  to 
digestion,  and  the  nourishment  of  the  system. 
Some  of  these  hinder  digestion  or  nutrition, 
or  they  interfere  with  these  processes.  The 
substances  referred  to  are  called  condiments. 

2.  Condiments    include    peppers,   spices,    cat- 
sups, certain  essential   oils,  and  tobacco. 

3.  It    may    seem    strange    to    class    tobacco 
among    condiments,  but    there    are    some    good 
reasons  for  placing  it  there.     It  is   an   aromatic 
plant   and   leaf,  and   probably   its    peculiar  taste, 
and    its    power   to   appease   hunger   temporarily, 
had    more   to   do   with    its    first    use   than   any 
other    cause.      At    different    times    it    has   been 
referred    to    as    a    tonic    and    stimulant    and    a 
condiment,  and   since  many   writers  still  classify 
it   as   the   latter,  we   have   so   given   it   here. 


STIMULANTS  AND  NARCOTICS.  157 

4.  Common  salt  has  not  here  been  mentioned 
as    a    condiment,    although    it  is  used    like    one; 
but    since    it    supplies    the    blood    with    one   of 
its    natural    and    necessary    constituents,    and     is 
supposed  to  aid    the   stomach    in   producing  cer- 
tain of    its  juices   which  aid    digestion,  it  seems 
better  to  exclude  it  from  the  list. 

5.  It  is  also  true  of   some  of  the  condiments 
that  they  have  a  slight  value  as  food.     Mustard, 
for  instance,  is  a  seed  which  has  slight  nourish- 
ing   qualities,    but    we    speak    of    mustard    and 
several    other    such    articles   as   condiments,  be- 
cause   they    are    mostly    used    as    such,    or    for 
the  purpose  of    stimulating    digestion. 

6.  Mustard,  cayenne-pepper,  horse-radish,  and 
ginger  are  the  condiments  most  commonly  used 
in    their    natural  forms,  although    each   is    also 
used    in     combination     with     other     substances. 
Both  epicures  and    chemists  have  wondered  and 
studied    to    learn    the    cause    of   their    peculiar 
effects  and  secret  of  their  power  to  excite. 

7.  People    interested   in   such     matters   claim, 
for  instance,  that  olives  stimulate  the  gustatory 
nerve,  or   nerve  of  taste,  and    the   upper  part  of 
the   throat,  and   so  increase   the  appetite.     It   is 
also    said   that   cayenne-pepper,  and   some   other 
varieties   of  pepper,  act   upon  the  lining   of  the 
stomach,  and   cause   an   unusual  flow  of  gastric- 


158  PHYSIOLOGY  PRIMER. 

juice,  and  for  this  reason  tend  to  counteract 
the  evil  effects  of  over-loading  the  stomach 
by  excessive  eating.  But  it  will  be  easily 
understood  that  if  the  stomach  is  thus  forced 
to  do  more  than  its  natural  amount  of  work 
it  will  suffer  in  the  end,  and  one  who  thinks 
to  take  advantage  of  the  stimulating  effects  of 
such  condiments,  and  unduly  indulges  his  appe- 
tite, will  surely  be  the  sufferer  for  his  short- 
sighted policy. 

8.  It  is  safe  to  say  of  these  condiments,  as  of 
other  questionable  articles  taken  into  the 
stomach,  that  a  person  should  be  able  to  give  a 
good  reason  for  using  them.  Before  giving 
them  an  opportunity  to  have  what  may  be  a 
disastrous  effect  upon  his  own  system  he  should 
be  fully  informed  of  their  nature.  These,  and 
some  other  articles,  when  allowed  to  overtax 
and  weaken  the  action  of  any  organs,  often 
create  an  unnatural  desire,  which  runs  into  a 
habit,  and  that  which  at  first  was  not  an 
appetite  may  soon  become  one.  It  is  for  this 
reason,  and  because  when  this  unnatural  appe- 
tite is  acquired  the  organs  themselves  are  in  an 
unnatural  condition,  that  persons  accustomed  to 
the  use  of  fiery  condiments  can  take  them  in 
much  larger  quantities  than  those  persons  who 
are  not. 


STIMULANTS  AND  NARCOTICS.  159 

9.  Black  pepper,  with  its  peculiar  taste, 
when  burned,  shows  by  its  ash  that  it  contains 
an  unusual  quantity  of  certain  valuable  salts, 
and  that  it  also  contains  a  quantity  of  another 
substance  known  as  phosphoric  acid.  Several 
other  ingredients  are  found  which  we  allude  to, 
because  black  pepper  has  a  more  important 
place  than  that  occupied  by  most  of  its  neigh- 
bors among  the  condiments. 

1C.  When  the  larger  portion  of  the  dark 
covering  on  the  pepper  berry  is  removed,  the 
result  is  what  is  known  as  white  pepper.  As 
has  already  been  hinted  in  speaking  of  cayenne- 
pepper,  it  cannot  be  spoken  of  as  favorably  as 
can  black  pepper.  It  is  nearly  always  irritating 
in  its  action,  and  is  called  an  irritant.  For 
this  reason  it  is  the  cause  of  many  cases  of 
dyspepsia,  and  other  forms  of  derangement  of 
the  stomach. 

11.  We  have  said  that  mustard  has  some  food 
value,  although    its  value  in  this   respect   is   not 
great.     Its   sharp   and    irritating  action  is  not  so 
lasting    as    that    of    cayenne-pepper,    and    some 
of    its   other  neighbors ;    therefore,  since   it   is   a 
mild    stimulant,    and   does    not    have    the    dis- 
advantages   that    accompany    most    other  stimu- 
lants, it  is   sometimes   of  service. 

12.  Perhaps  you  have  been   so  situated  as  to 


160  PHYSIOLOGY  PRIMER. 

be  very  hungry,  with  nothing  before  you  to  eat 
but  a  piece  of  very  tough  meat ;  you  had,  then, 
to  eat  the  meat  or  nothing.  The  stomach 
might  prove  incompetent  to  digest  such  a  meal, 
but  if  the  meat  were  thoroughly  chewed  and 
taken  with  a  little  mustard,  the  mustard 
might  furnish  a  needed  stimulant,  of  consid- 
erable service  to  digestion. 

13.  This  is  not  recommended  as  a  wise  course 
to  pursue  when  tender  and  easily  digested   food 
can  be  obtained  ;   but  mustard,  in  case  of  neces- 
sity,   may    sometimes    serve     as    the     whip     or 
stimulus    to     make     indigestible     things     partly 
digestible,   and    to    give    exhausted    stomachs    a 
little    more     appetite.      Ginger     contains     much 
starch  and  gum,  and  owes  its  peculiar  pungency 
to  its  oil  and  resin. 

14.  Hor.se-radish     is     a    root,     which,    finely 
grated,  is   an    appetizer.     As   such   it   is   perhaps 
better    than     either    mustard    or   black    pepper, 
although     not     so     good     for     general     use     on 
account   of    the    fact    that   it   is   a   greater   irri- 
tant    to     the     stomach.       Horse-radish     has    a 
slight     food    value,    although     not     enough    to 
warrant   its   use   on   that   account. 

15.  Curry-powders   are   freely   used   by    many 
people,   and    consist   of    a    mixture    of    various 
condiments   such    as    ginger,  black    pepper,  gar- 


STIMULANTS  AND  NARCOTICS. 


lie,  etc.,  and  we  can  judge  of  their  nature 
by  the  qualities  of  the  various  ingredients 
used  in  their  manufacture.  Curry  was  first 
used  among  the  natives  of  Ceylon,  as  a  dress- 
ing for  rice,  and  was  thought  to  make  it 
more  pleasant  to  the  taste. 

16.  Catsups    and    sauces,    now    so    commonly 
and     extensively     used,    are     made    of    various 
fruits,    flavors,    and     condiments,    in     order     to 
cover   the   taste  of    some   foods,    to   give   special 
flavor  to   others,  and    to    stimulate   the   appetite 
and   the   digestive  apparatus.     It  is   safe   to   say 
of  such   articles,  as   a   class,  that  they   are  gen- 
erally  used   to   excess   at  the   present  time   and 
are  very  injurious. 

17.  Diseases    of    the    stomach    and    digestive 
organs,  and  especially  of  the   kidneys,  are   more 
common  now  than  formerly,  and  it   is    believed 
that  this  has  been  brought  about,  largely,  by  the 
habit  of  frequent  and  unnatural  stimulants,  and 
especially    by    eating    foods    made    over-hot    by 
strong   peppers,  sauces,  etc. 

18.  Since  delicate  and   appetizing    flavors  and 
extracts   can   be  obtained   without   all   this   dan- 
ger  from   irritants,  how   much    better   it   would 
be  if   these    could    become    the   condiments    in 
general    use,   rather    than    the    more   fiery   and 
dangerous   ones   now   so   commonly   taken. 


162  PHYSIOLOGY  PRIMER. 

TOBACCO. 

SECT.  VII.  —  1.  Although  tobacco  has  already 
been  classified  as  a  condiment,  if  we  turn  to 
works  treating  it  in  its  effects  upon  the  sys- 
tem we  shall  find  it,  like  alcohol,  among  the 
toxics.  Here  may  be  found  the  clearest  and 
fullest  accounts  of  it.  When  first  freely  used 
it  generally  causes  dizziness,  trembling  of  the 
limbs,  faintness,  sickness  of  the  stomach,  and 
cold  sweats.  The  pulse  is  weak  and  quiver- 
ing, the  breathing  is  irregular  and  the  sight 
dimmed.  If  the  chewing  and  smoking  which 
produces  these  effects  has  not  been  excessive 
these  symptoms  soon  pass  away.  If  tobacco 
is  slightly  used  the  system  soon  becomes 
accustomed  to  it,  and  learns  to  tolerate  it, 
and  at  length  an  appetite  is  acquired  for  it. 

2.  Experience  has  shown  that  the  system 
will  accommodate  itself  to  very  unusual  and 
unnatural  conditions;  but  because  it  acquires  a 
toleration  for  alcohol,  and  none  of  the  violent 
symptoms  mentioned  follow  immediately  on  its 
use,  this  by  no  means  proves  that  such  articles 
are  useful  or  even  harmless.  Not  even  the  first 
effects  of  milk,  or  meat,  or  fruit,  or  of  the 
cereals,  are  ever  like  those  of  tobacco,  and  this 
shows  that  the  latter  is  regarded  by  nature  as 
an  unfriendly  element. 


STIMULANTS  AND  NARCOTICS.  163 


EFFECTS   OF   TOBACCO. 

3.  Tobacco  is  not  nearly  so  likely  to  change 
the  structure  of  an   organ   as   is   alcohol,  but   it 
rather   affects   the    action    of    that    organ.      Yet 
permanent  changes,  especially  in  the  blood-vessels 
and  in  the  nervous  system,  frequently  result  from 
its  use. 

4.  Cases  are  given  in  medical  works  in  which 
excessive   smoking   has   caused    death;   in    other 
cases    it   has   caused   paralysis,    and,   in    general, 
the  use  of  tobacco  tends  to  bring  about   dyspep- 
sia, palpitation  of  the  heart,  and  various  diseases 
of  the  nerves. 

EFFECTS    ON    THE    YOUNG. 

5.  While  tobacco   acts   injuriously  on   adults, 
its   effects   upon    young   and   growing    boys    are 
much  more  damaging.     At  one  time  orders  were 
given  in  the  United  States   Naval   Academy   for 
the  students  to  refrain  from  the  use   of  tobacco. 
Subsequently  they  were  allowed  to  return  to   its 
use,  when  the  evil  effects   became   so   noticeable 
that    the    young    men    were    again    ordered    to 
desist. 

6.  It  is   an    interesting    and    suggestive    fact 
that  even  those  persons  who  do   not  admit  that 
tobacco  injures  themselves   are  agreed   as   to  its 


164  PHYSIOLOGY  PRIMER. 

harmful  effects  upon  the  young,  and  nearly  all 
such  persons  favor  laws  which  would  prevent 
its  sale  in  any  form  to  those  under  age. 

7.  By    students    who    have    made    a   special 
study  of  the  subject,  it  is   believed   that   a   large 
part  of  our  population  of  young  men  have  been 
greatly  injured  by  the  prevalent  use  of  tobacco, 
and  even  among  adults  the  habit  has  become  so 
general,   and   in   many   cases   so    excessive,    that 
special  diseases  may  be  directly  traced  to  it.     Not 
alone   does  it  injure   the   person   addicted   to   its 
use,   but   its   special    injurious    effects    are    even 
transmitted  to  his  descendants. 

SMOKING. 

8.  Tobacco-smoking   increases  the  rapidity  of 
the    pulse,    and    both    in   smoking   and   chewing 
there  is  an  unnatural  stimulation  to  the  salivary 
glands.     For  this   reason  their  usefulness  as  aids 
in  the  process  of  digestion  is  interfered  with. 

9.  It  is  sometimes  said   that  while  occasional 
smoking,   even   if  it    has   injurious   effects,   does 
not     permanently     injure     the     system,     it     is 
equally    true    that    there    are  comparativly    few, 
occasional    smokers ;    but,    on    the    other    hand, 
persons  who  smoke  at  all,  are  very  apt  to  smoke 
to  excess,  and  excessive  smoking  makes,  in  time, 
a     permanent     impression     upon     the     nervous 
system. 


STIMULANTS  AND  NARCOTICS.  165 


SMOKING    CHECKS    GROWTH. 

10.  There  is   no  longer   any   question   among 
those  who  have  investigated  the  subject  that  the 
growth   of  the   young   is    seriously   checked    by 
smoking.     On  this  account,  and   because  the  use 
of  alcohol    is    much    less    common,   among    the 
young,  than  the  use  of  tobacco,  the  latter  is,  at 
the  present  time,  working  greater  injury   among 
boys   than   the   former. 

11.  Surely   any   substance   which,  when   first 
taken,   will   produce   violent    effects,  which    has 
caused  death  when   applied  for    a   long   time   to 
a  raw   surface   on  the   body,  which    has    caused 
irritation,  resulting   in    cancer,  ought   not    to   be 
in  common  and  daily  use  among  men  and  boys. 

12.  While  all  forms  of  smoking  are  injurious, 
it  has  been  found   that   the  use  of  the  cigarette 
is   more  harmful  than    the  cigar  or  pipe.     It  so 
seriously   undermines    the   power   of  self-control 
that  persons  once  addicted  to  its   use  very  often 
find  it  impossible  to  break  up  and  abandon  the 
habit.     Anything  that   so  weakens  the  power  of 
the   will,   even   though    it   does   not    injure    the 
health  of  the  body,  is  certainly  an  enemy  to  be 
avoided.       The     mastery    of    one's    self    is     all- 
important,  and  what  interferes  with  that  mastery 
should   not    be  harbored    in    the    system ;    or  if 


166  PHYSIOLOGY  PRIMER. 

once  taken  up  the  practice  should  be  abandoned 
when  the  effects  are  learned. 

13.  In   view   of  what   is   known   of  the   evil 
effects   of  tobacco  on   the  young,  several   of  the 
states   have   already   passed   laws   prohibiting  its 
sale  to  those  under  sixteen  years  of  age.      It   is 
to  be  hoped  that  the   remaining  states  will   ere- 
long take  similar  action. 

14.  No  one  ever   regretted   that   he  had  not 
formed  the  habit   of  using  tobacco,  while   thou- 
sands   have    had    great   reason    for   sorrow    that 
they    began    its    use.     Since    this  is   so,  and    in 
view  of  all  the  known  facts  regarding  its  effects, 
it  would  seem   that  no    one   could  justify    him- 
self in  beginning. 

QUESTIONS. 

SECT.  I.  —  1.  Why  are  fluids  needed  in  the  system  ?  What 
are  the  chief  drinks  of  mankind  ? 

SECT.  II.  —  3.  What  food-substances  are  found  in  tea,  coffee, 
and  cocoa?  Which  contains  the  most?  Which  the  least? 

7.  What  effect  does  tea  have  on  the  system? 

8.  Effects  of  coffee  ? 

11.  Does  milk,  in  tea,  add  to  its  value?  Why  not?  What  is 
the  effect  of  drinking  large  quantities  of  tea  and  milk?  What 
can  you  say  of  the  action  of  cream  in  tea? 

13.  The  drinking  of  tea  or  coffee  by  children.     Can  you  name 
any  substitute  for  tea  or  coffee  for  children? 

14.  Speak  of  the  food  value  of  cocoa.    Describe  its  mode  of 
preparation.    What  gives  cocoa  the  most  of  its  value  as  a  food? 

15  How  is  cocoa  adulterated?    What  is  cocoa  butter? 


STIMULANTS  AND  NARCOTICS.  167 

SECT.  III.  —  1.  Why  is  it  important  to  understand  the  nature 
of  alcohol  ? 

2.  What  is  the  one  important  element  in  spirituous  liquors? 

3.  What  is  alcohol  and  what  are  its  leading  qualities? 

4.  Mention  the  two  general  classes  of  spirituous  liquors. 
6.   How  is  fermentation  produced  ? 

6.  Distillation? 

7.  What  is  the  composition  of  wine? 

8.  Of  whfct  is   beer   composed? 

9.  How    is    brandy   made? 

10.  How  is  rum  produced? 

11.  From  what  is  whiskey  made? 

12.  What  is  gin? 

13.  What  can  you  say  of  the  genuineness  of  liquors  ? 

14.  How  do  we  know  that  alcohol  is  not  valuable  as  a  food  ? 

15.  What  is  the  nature  of  alcohol  ? 

16.  Why  do  we  know  alcohol  is  not  a  flesh-forming  food? 

17.  Why  is  it  known  not  to  be  a  heat-producing  food  ? 

SECT.  IV.  —  1.  WThy  has  alcohol  sometimes  been  thought  to 
be  valuable  as  a  food? 

2.  What  can  you  say  of  the  power  of  alcohol  to  produce  a 
habit?    What  are  some    other    substances  which   have   similar 
power  ? 

3.  What  of  the  effects  of  alcohol  on  nutrition? 

4.  What  of  its  effects  on  the  digestive  organs? 

5.  What  did  science  formerly  teach  regarding  alcohol  ?    What 
does  experience  teach  ? 

7.  How  is  alcohol  regarded  in  the  army  and  navy  f 

8,  9.   In  training  for  athletics  ? 

SECT.  V. —  1,  2.  Speak  of  the  frequency  of  deaths  among 
liquor  dealers. 

3.  What  do  life  insurance  tables  show  in  regard  to  the  effects 
of  liquor? 

'4;  How  does  alcohol  affect  the  frequency  of  disease?  What 
organ  is  most  affected  by  it? 


168  PHYSIOLOGY  PRIMER. 

5.   Mention  some  organs  affected  by  "  moderate  drinking." 

10.  What  is  one  good  reason  for  total  abstinence  ? 

11.  What  way  is  safe  in  regard  to  forming  drinking  habits? 

12.  What  is  the  safest  maxim  ? 

SECT.  VI.  — 1?  2.   Name  the  principal  condiments? 

3.  Why  is  tobacco  called  a  condiment  ? 

4.  Why  is  not  common  salt  called  a  condiment  ? 

5.  6.    What  can  you  say  of  the  food  value  of  condiments? 

7.  What  is  the  action  of  olives?    Cayenne  pepper?    What  is 
the  effect  of  forcing  the  stomach  to  unnatural  activity  ? 

8.  Why  can  some  persons  take  more  fiery  condiments   than 
others  ? 

9.  What  is  valuable  in  black  pepper? 

10.  What  is  white  pepper  ? 

11.  Speak  of  the  value  of  mustard? 

12.  13.    When  is  mustard  useful? 

14.  What  can  you  say  of  ginger?    Of  horse-radish ? 

15.  What   are    curry   powders?    Where   did   they  originate? 
Are  they  good  or  bad  to  use? 

16.  What  is  the  general  effect  of  catsups,  sauces,  etc.? 

17.  What  is  better  than  such  sauces? 

SECT.  VII.  —  1.    What  is   the   nature  of  tobacco?    What  are 
its  first  effects? 

3.  What  is  the  action  of  tobacco  on  the  human  organs? 

4.  Mention  some  of  its  known  effects  on  health. 

5.  What  course  has  been   pursued  regarding  tobacco  in  the 
United  States  Naval  Academy? 

6.  What  is  the  usual  opinion  of  the  effect  of  tobacco  among 
persons  who  use  it? 

7.  What  can  you  say  of  its  influence  on  young  men? 

8.  What  are  the  effects  of  tobacco-smoking? 

9.  What  can  you  say  of  occasional  smokers? 

12.  Cigarette  smoking? 

13.  What   laws   relating   to   the   sale   of  tobacco  have  been 
passed  by  some  states? 

14.  Name  all  the  reasons  you  can  think  of  why  one  should 
not  use  tobacco? 


GLOSSAEY. 


Ari-me'nt.    Nourishment. 

A-nat'o-my.  The  science  of  the 
structure  of  organized  bodies. 

A-or'ta.  The  great  artery  which 
comes  from  the  heart,  and  passes 
down  by  the  backbone. 

Au'ri-cle.  A  name  given  to  two 
cavities  of  the  heart. 

Bi'ceps.  A  muscle  on  the  front  of 
the  arm. 

Cap'il-la-ry.    A  hairlike  tube. 

Ca-rot'id.  A  name  applied  to  sev- 
eral arteries  in  the  neck. 

Cor'iie-a.  The  circular,  transparent 
membrane  in  front  of  the  eye. 

Cor'pus-cle.    A  minute  particle. 

Cu'ti-cle.  The  upper  layer  of  the 
skin. 

Cu'tis.    The  deep  layer  of  the  skin. 

Dan'druff.  A  scurf  which  forms  on 
the  scalp,  and  comes  off  in  small 
scales. 

Di'a-phragm.  A  sheet  made  of 
muscle  and  fibrous  membrane,  be- 
tween the  chest  and  abdomen. 

En-am'el.  The  hard  and  polished 
substance  which  covers  the  crown 
of  a  tooth. 

Gas'tric.  Pertaining  to  the  stomach. 

Gland.  A  name  given  to  many  or- 
gans which  take  part  in  the  pro- 
cesses of  life. 

Hy'giene.    The  science  of  health. 


I'ris.  A  colored  muscular  membrane 

in  the  anterior  chamber  of  the  eye. 
Lach'ry-mal.  Pertaining  to  tears. 
Lymph.  Contents  of  the  lymphatic 

vessels. 
MI'tral.    Like  a  miter,  or  bishop's 

cap. 
Nar-c5t/ic.    That  which  soothes  or 

stupefies. 

CE-soph'a-gus.    The  gullet. 
Pan'cre-as.    An  organ  of  digestion. 

The  sweetbread  in  calves. 
Phys-i-ol'o-gy.     The  science  of  the 

functions  of  organized  bodies. 
Plas'ma.    The   watery  part  of  the 

blood. 
Plex'us.      A   network   of   vessels, 

nerves,  or  fibers. 
Poret    The  outlet  of  a  sweat  duct  or 

gland. 
Piirmo-na-ry.     Pertaining  to  the 

lungs. 
Pu'pil.    The  central  opening  in  the 

iris. 
Py-lo'rus.    A  muscular  ring  which 

surrounds  the  outlet  of  the  stomach. 
Res-pi-ra'tion.      The     process     of 

breathing. 
Ret'i-na.    The  terminal  fibers  of  the 

optic  nerve,  lining  the  back  part  of 

the  eye. 

Sa-H'va.    Spittle. 
Sar-tS'ri-us.     A  muscle  extending 


170 


GLOSSARY. 


from  the  hip  to  the  leg,  on  the 

front  of  the  thigh. 
Scle-rot'ic.    A  term  applied  to  the 

outer  coat  of  the  eye. 
Se-ba'ceoiis.    Fatty,  or  tallowy. 
Sgm-i-lu'nar.    Shaped  like  a  half- 
moon. 
Sta-pe'di-us.    A  very  small  muscle 

in  the  drum  of  the  ear. 
Stim'u-lant.    That  which  goads  or 

excites. 

Syn-o'via.    Joint-water. 
TSn'don.    A  cord  of  white,  fibrous 

tissue  connected  with  a  muscle. 
TSn'don  of  A-chil'les.  The  tendon 

oi   the  gastrocnemius  and  soleus 


muscles  inserted  in  the  heel.  It 
was  fabled  that  this  was  the  only 
part  in  which  Achilles  was  vul- 
nerable. 

Tho'rax.    The  chest. 

Tri-chi'na.  A  small  worm  that  lives 
in  the  muscles  of  pigs,  and  of  some 
other  animals,  and  of  men. 

Tri-cus'pid.    Three-pointed. 

Vgn'tri-cle.  A  name  given  to  sev- 
eral small  cavities  in  the  body. 

Ver'te-bra.  One  of  the  bones  which 
make  the  backbone; 

Vo'cal  cords.  Two  fibrous  bands 
that  form  the  margins  of  the  glot- 
tis, or  upper  part  of  the  larynx. 


INDEX. 


ABDOMEN,  76. 
Absorption,  76,  88. 
Adam's  apple,  99. 
Air,  95. 
Air-cells,  101. 
Air,  impure,  104. 
Alcohol,  72. 

"        effects  on  the  skin,  22. 

"        effects  on  muscles,  31. 

"        effects   on    the    heart    and 
blood-vessels,  46. 

"        effects  on  the  blood,  57. 

"        effects  on  digestive  organs, 
90. 

"       effects    on    respiratory   or- 
gans, 105. 

11        effects  on  the  nervous  sys- 
tem, 124. 

"        effect  on  bones,  137. 
Ale,  72. 
Alimentary  canal,  77. 

"  "      fluids  of,  87. 

"  "      divisions  of,  87. 

Anatomy,  9. 
Animals,  60. 
Animal  food,  61. 
Ankle,  132. 
Aorta,  35,  39. 
Arm,  11,  132. 
Arteries,  35,  38,  46. 
Atlas,  131. 

BACKBONE,  129, 
Barley,  62. 
Bathing,  26,  57. 


Beans,  63. 

Beef,  24,  61. 

Beer,  72. 

Belly,  76. 

Biceps,  26,  43. 

Bile,  86. 

Blood,  20,  30,  35,  42,  50. 

Blood-vessels,  35,  10,  42,  47. 

Body,  parts  of,  11. 

Bodily  heat,  18, 

Bones,  35,  130. 

"      structure  of,  134. 
Bowels,  77,  85. 
Brain,  108. 
Brandy,  72. 
Bread,  63. 
Breast-bone,  132. 
Breathing,  96. 
Bronchial  tnbes,  101. 
Bunion,  136. 
Burn,  12. 

CAKE,  64,  89. 

Cancer,  71. 

Candy,  57,  89. 

Capillaries,  35,  39,  40,  46,  55. 

Carbonic-ackt  gas,  104. 

Carotid  artery,  45. 

Cartilage,  99, 133. 

Chest,  76. 

Chloral,  1-26. 

Cigarettes,  32,  126. 

Circulation,  45. 

Clothing,  19. 

Clots,  31. 

171 


172 


INDEX. 


Coffee,  68. 
Cold,  21. 
Collar-bone,  132. 
Cooking,  61,  63. 
Corn,  62. 
Corpuscles,  52. 
Cucumbers,  90. 
Cutis,  12. 
Cuticle,  12. 

DANDRUFF,  13. 
Delirium  tremens,  125. 
Diaphragm,  76, 113. 
Digestion,  76,  78. 
Drinking,  108. 
Drinking-water,  65. 
Drum  of  the  ear,  123. 
Dyspepsia,  89,  91. 

EAR,  108, 123. 
Eggs,  62. 
Elephant,  110. 
Enamel,  80. 
Eustachian  tube,  123. 
Exercise,  30,  57, 137. 
Expression,  30. 
Eye,  118. 
Eyes,  care  of,  122. 

FAINTING,  56. 
Fever,  13,  20. 
Fish,  61. 
Flesh,  24,  35. 
Food,  24,  57,  60. 
Foot,  11,  132. 

"     care  of,  136. 
Fore-arm,  11,  132. 
Fowls,  61. 
Frame,  care  of,  135. 

"        growth  of,  137. 
Framework,  129. 

GALL-BLADDER,  87. 
Garden  vegetables,  63. 
Gastric  juice,  83. 


Gates,  41. 

Gland,  lymphatic,  56. 
Glycogen,  87. 
Green  apples,  90. 
Gullet,  76. 

HAIR,  15. 
Hand,  11,  132. 
Headaches,  69. 
Heart,  35,  37,  42. 
Hip-bones,  132. 
Hygiene,  10. 

IMPURITY,  58. 
Insanity,  125. 
Intestines,  77. 
Intestinal  juice,  87. 
Intoxicating  drinks,  65. 
Involuntary  muscle,  29- 

JAUNDICE,  87. 
Joints,  132. 

KIDNEYS,  77. 
Knee-cap,  132. 

LAMB,  61. 
Larynx,  99. 
Laudanum,  70. 
Lead  pipes,  65. 
Left  auricle,  39. 
Leg,  11,  132. 
Lens,  121. 
Ligaments,  134. 
Lights,  96. 
Lips,  79. 
Liver,  76,  86. 
Lung,  102. 

Lymphatic  glands,  56. 
Lymphatics,  50,  55. 

MARROW,  134. 
Meats,  24. 
Mineral  food,  64. 
Mitral  valve,  41- 


INDEX. 


173 


Morphine,  70 

RAW  HAM,  61. 

Mouth,  77 

Raw  sausages,  61. 

Mumps,  82. 

Repair,  53. 

Muscles,  24,  25,  29,  43,  120. 

Respiration,  95. 

Mustard,  67. 

Retina,  121. 

Mutton,  24,  61. 

Ribs,  131. 

Rice,  62. 

NAILS,  17. 

Right  auricle,  37,  40. 

Narcotics,  22,  60,  67,  69 

Rubbing,  21. 

Nerves,  20,  108,  111. 

Rum,  72. 

Nerve-centers,  111. 

Rye,  62. 

Nervous  system.  108. 

Nicotine,  58,  106.  126. 

SALIVA,  81,  82. 

Nose,  i»7. 

Salivary  glands,  81. 

Nourishment,  53. 

Salt,  18,  21,  64. 

Sartorius,  26. 

OATMEAL,  62. 

Scar,  12. 

Oats,  62. 

Sciatic  nerve,  112. 

Oesophagus,  76, 

Sebaceous  glands,  16. 

Olfactory  nerves,  lli». 

Semilunar  valves,  41. 

Opium,  60,  126. 

Shoes,  tight,  136. 

Optic  nerve,  120. 

Shoulder,  132. 

Overflow,  55. 

Shoulder-blade,  132. 

Oxygen,  53,  54,  102. 

Skeleton,  129. 

Oysters,  62. 

Skin,  11,  17,  19,  20,  21. 

Smell,  98. 

PANCREAS,  76. 

"       bad,  104. 

Pancreatic  juice,  87. 

"       nerves  of,  112. 

Pastry,  64 

Smoker's  heart,  48. 

Pease,  63. 

Snoring,  98. 

Pepper,  67. 

Spinal  canal,  130. 

Perspiration,  13,  20. 

Spleen,  77. 

Physiology,  9. 

St.  Martin,  85. 

Pickles,  57. 

Stapedius,  26. 

Pie,  89. 

Stimulant,  67,  90,  91. 

Plants,  60. 

Stomach,  77,  83,  89,  90,  9L 

Plasma,  52. 

Stomach-glands,  83. 

Pores,  14. 

Sweat,  14. 

Pork,  61. 

Syringe,  44. 

Porter,  72. 

Sweat-glands,  14,  15,  19. 

Potato,  62. 

Sweetbread,  87. 

Pulmonary  artery,  38,  112. 

Sweetmeats,  57. 

"           veins,  39. 

Synovia,  133. 

Pulse,  45. 

Pylorus,  85. 

TEA,  68,  69. 

174: 


INDEX. 


Teeth,  79. 
Tendons,  28. 
Tendon  of  Achilles,  28. 
Thigh,  11,  132. 
Thorax,  76. 
Tongue,  81. 
Tobacco,  10,  58,  70. 

"         effect  of,  on  bones,  137. 

"          effects  of,  on  skin,  22. 

"          effects  of,  on  muscles,  32. 

"          effects  of,  on  the  heart,  47. 

"          effects  of,  on  boys,  71. 

"          effects  of,  on  stomach,  92. 

"         effects  of,  on  respiratory  or- 
gans, 105. 

"         effect  of,  on  the  breath,  106. 

"         effects  of,  on  the    nervous 
system,  124. 

"         effects  of,  on  the  frame,  137. 
Trachea,  96. 
Trichina,  61. 
Tympanum,  123. 
Typhoid  fever,  66. 

UNRIPE  FRUITS,  57. 


VALVES,  41. 
Valve,  tricuspid,  41. 

"       seniilunar,  41. 

"       mitral,  41. 
Vegetable  food,  62. 
Vein,  46, 
Veins,  35. 
Ventricle,  37,  39. 
Vertebrae,  129. 
Vertebrates,  130. 
Vocal  cords,  99. 
Voice,  95. 
Voluntary  muscle,  2ft. 

WALKINO,  27. 
Waste,  53. 
Water,  60,  64. 
Wear,  53. 
Whale,  110. 
Wheat,  62. 
Whisky,  19,  72. 
Windpipe,  96,  100. 
Wines,  71. 
Worms,  16. 
Wry  neck,  12. 


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